Author: "Nicola Astudillo-Defru" - Searchworks@Jio Institute Digital Library Search Results

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73 results on '"Nicola Astudillo-Defru"'

1. Validation of a Third Planet in the LHS 1678 System

Author: Michele L. Silverstein, Thomas Barclay, Joshua E. Schlieder, Karen A. Collins, Richard P. Schwarz, Benjamin J. Hord, Jason F. Rowe, Ethan Kruse, Nicola Astudillo-Defru, Xavier Bonfils, Douglas A. Caldwell, David Charbonneau, Ryan Cloutier, Kevin I. Collins, Tansu Daylan, William Fong, Jon M. Jenkins, Michelle Kunimoto, Scott McDermott, Felipe Murgas, Enric Palle, George R. Ricker, Sara Seager, Avi Shporer, Evan Tey, Roland Vanderspek, and Joshua N. Winn
Subjects: Exoplanet systems, Transit photometry, Transit timing variation method, M dwarf stars, Astronomy, QB1-991
Abstract: The nearby LHS 1678 (TOI-696) system contains two confirmed planets and a wide-orbit, likely brown-dwarf companion, which orbit an M2 dwarf with a unique evolutionary history. The host star occupies a narrow “gap” in the Hertzsprung–Russell diagram lower main sequence, associated with the M dwarf fully convective boundary and long-term luminosity fluctuations. This system is one of only about a dozen M dwarf multiplanet systems to date that hosts an ultra-short-period planet (USP). Here we validate and characterize a third planet in the LHS 1678 system using TESS Cycle 1 and 3 data and a new ensemble of ground-based light curves. LHS 1678 d is a 0.98 ± 0.07 R _⊕ planet in a 4.97 day orbit, with an insolation flux of ${9.1}_{-0.8}^{+0.9}\,{S}_{\oplus }$ . These properties place it near 4:3 mean motion resonance with LHS 1678 c and in company with LHS 1678 c in the Venus zone. LHS 1678 c and d are also twins in size and predicted mass, making them a powerful duo for comparative exoplanet studies. LHS 1678 d joins its siblings as another compelling candidate for atmospheric measurements with the JWST and mass measurements using high-precision radial velocity techniques. Additionally, USP LHS 1678 b breaks the “peas-in-a-pod” trend in this system although additional planets could fill in the “pod” beyond its orbit. LHS 1678's unique combination of system properties and their relative rarity among the ubiquity of compact multiplanet systems around M dwarfs makes the system a valuable benchmark for testing theories of planet formation and evolution.
Published: 2024
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2. Company for the Ultra-high Density, Ultra-short Period Sub-Earth GJ 367 b: Discovery of Two Additional Low-mass Planets at 11.5 and 34 Days

Author: Elisa Goffo, Davide Gandolfi, Jo Ann Egger, Alexander J. Mustill, Simon H. Albrecht, Teruyuki Hirano, Oleg Kochukhov, Nicola Astudillo-Defru, Oscar Barragan, Luisa M. Serrano, Artie P. Hatzes, Yann Alibert, Eike Guenther, Fei Dai, Kristine W. F. Lam, Szilárd Csizmadia, Alexis M. S. Smith, Luca Fossati, Rafael Luque, Florian Rodler, Mark L. Winther, Jakob L. Rørsted, Javier Alarcon, Xavier Bonfils, William D. Cochran, Hans J. Deeg, Jon M. Jenkins, Judith Korth, John H. Livingston, Annabella Meech, Felipe Murgas, Jaume Orell-Miquel, Hannah L. M. Osborne, Enric Palle, Carina M. Persson, Seth Redfield, George R. Ricker, Sara Seager, Roland Vanderspek, Vincent Van Eylen, and Joshua N. Winn
Subjects: Exoplanet detection methods, Exoplanet systems, Exoplanets, Extrasolar rocky planets, Astrophysics, QB460-466
Abstract: GJ 367 is a bright ( V ≈ 10.2) M1 V star that has been recently found to host a transiting ultra-short period sub-Earth on a 7.7 hr orbit. With the aim of improving the planetary mass and radius and unveiling the inner architecture of the system, we performed an intensive radial velocity follow-up campaign with the HARPS spectrograph—collecting 371 high-precision measurements over a baseline of nearly 3 yr—and combined our Doppler measurements with new TESS observations from sectors 35 and 36. We found that GJ 367 b has a mass of M _b = 0.633 ± 0.050 M _⊕ and a radius of R _b = 0.699 ± 0.024 R _⊕ , corresponding to precisions of 8% and 3.4%, respectively. This implies a planetary bulk density of ρ _b = 10.2 ± 1.3 g cm ^−3 , i.e., 85% higher than Earth’s density. We revealed the presence of two additional non-transiting low-mass companions with orbital periods of ∼11.5 and 34 days and minimum masses of ${M}_{{\rm{c}}}\sin {i}_{{\rm{c}}}$ = 4.13 ± 0.36 M _⊕ and ${M}_{{\rm{d}}}\sin {i}_{{\rm{d}}}$ = 6.03 ± 0.49 M _⊕ , respectively, which lie close to the 3:1 mean motion commensurability. GJ 367 b joins the small class of high-density planets, namely the class of super-Mercuries, being the densest ultra-short period small planet known to date. Thanks to our precise mass and radius estimates, we explored the potential internal composition and structure of GJ 367 b, and found that it is expected to have an iron core with a mass fraction of ${0.91}_{-0.23}^{+0.07}$ . How this iron core is formed and how such a high density is reached is still not clear, and we discuss the possible pathways of formation of such a small ultra-dense planet.
Published: 2023
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3. Characterization of a Set of Small Planets with TESS and CHEOPS and an Analysis of Photometric Performance

Author: Dominic Oddo, Diana Dragomir, Alexis Brandeker, Hugh P. Osborn, Karen Collins, Keivan G. Stassun, Nicola Astudillo-Defru, Allyson Bieryla, Steve B. Howell, David R. Ciardi, Samuel Quinn, Jose M. Almenara, César Briceño, Kevin I. Collins, Knicole D. Colón, Dennis M. Conti, Nicolas Crouzet, Elise Furlan, Tianjun Gan, Crystal L. Gnilka, Robert F. Goeke, Erica Gonzales, Mallory Harris, Jon M. Jenkins, Eric L. N. Jensen, David Latham, Nicholas Law, Michael B. Lund, Andrew W. Mann, Bob Massey, Felipe Murgas, George Ricker, Howard M. Relles, Pamela Rowden, Richard P. Schwarz, Joshua Schlieder, Avi Shporer, Sara Seager, Gregor Srdoc, Guillermo Torres, Joseph D. Twicken, Roland Vanderspek, Joshua N. Winn, and Carl Ziegler
Subjects: Exoplanet astronomy, Extrasolar rocky planets, Mini Neptunes, Astronomy, QB1-991
Abstract: The radius valley carries implications for how the atmospheres of small planets form and evolve, but this feature is visible only with highly precise characterizations of many small planets. We present the characterization of nine planets and one planet candidate with both NASA TESS and ESA CHEOPS observations, which adds to the overall population of planets bordering the radius valley. While five of our planets—TOI 118 b, TOI 262 b, TOI 455 b, TOI 560 b, and TOI 562 b—have already been published, we vet and validate transit signals as planetary using follow-up observations for four new TESS planets, including TOI 198 b, TOI 244 b, TOI 444 b, and TOI 470 b. While a three times increase in primary mirror size should mean that one CHEOPS transit yields an equivalent model uncertainty in transit depth as about nine TESS transits in the case that the star is equally as bright in both bands, we find that our CHEOPS transits typically yield uncertainties equivalent to between two and 12 TESS transits, averaging 5.9 equivalent transits. Therefore, we find that while our fits to CHEOPS transits provide overall lower uncertainties on transit depth and better precision relative to fits to TESS transits, our uncertainties for these fits do not always match expected predictions given photon-limited noise. We find no correlations between number of equivalent transits and any physical parameters, indicating that this behavior is not strictly systematic, but rather might be due to other factors such as in-transit gaps during CHEOPS visits or nonhomogeneous detrending of CHEOPS light curves.
Published: 2023
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4. LHS 1815b: The First Thick-disk Planet Detected by TESS

Author: Tianjun Gan, Avi Shporer, John H. Livingston, Karen A. Collins, Shude Mao, Alessandro A. Trani, Davide Gandolfi, Teruyuki Hirano, Rafael Luque, Keivan G. Stassun, Carl Ziegler, Steve B. Howell, Coel Hellier, Jonathan M. Irwin, Jennifer G. Winters, David R. Anderson, César Briceño, Nicholas Law, Andrew W. Mann, Xavier Bonfils, Nicola Astudillo-Defru, Eric L. N. Jensen, Guillem Anglada-Escudé, George R. Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M Jenkins, Gabor Furesz, Natalia M. Guerrero, Elisa Quintana, Joseph D. Twicken, Douglas A. Caldwell, Peter Tenenbaum, Chelsea X. Huang, Pamela Rowden, and Bárbara Rojas-Ayala
Subjects: Astrophysics
Abstract: We report the first discovery of a thick-disk planet, LHS 1815b (TOI-704b, TIC 260004324), detected in the Transiting Exoplanet Survey Satellite (TESS) survey. LHS 1815b transits a bright (V = 12.19 mag, K = 7.99 mag) and quiet M dwarf located 29.87 ± 0.02 pc away with a mass of 0.502 ± 0.015 M⊙ and a radius of 0.501 ± 0.030 R⊙. We validate the planet by combining space- and ground-based photometry, spectroscopy, and imaging. The planet has a radius of 1.088 ± 0.064 R⊕ with a 3σ mass upper limit of 8.7 M⊕. We analyze the galactic kinematics and orbit of the host star LHS 1815 and find that it has a large probability (Pthick/Pthin = 6482) to be in the thick disk with a much higher expected maximal height (Zmax = 1.8 kpc) above the Galactic plane compared with other TESS planet host stars. Future studies of the interior structure and atmospheric properties of planets in such systems using, for example, the upcoming James Webb Space Telescope, can investigate the differences in formation efficiency and evolution for planetary systems between different Galactic components (thick disks, thin disks, and halo).
Published: 2020
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5. GJ 1252 b: A 1.2 R⊕ Planet Transiting an M3 Dwarf at 20.4 pc

Author: Avi Shporer, Karen A. Collins, Nicola Astudillo-Defru, Jonathan Irwin, Xavier Bonfils, Kevin I. Collins, Elisabeth Matthews, Jennifer G. Winters, David R. Anderson, James D. Armstrong, David Charbonneau, Ryan Cloutier, Tansu Daylan, Tianjun Gan, Maximilian N. Günther, Coel Hellier, Keith Horne, Chelsea X. Huang, Eric L. N. Jensen, John Kielkopf, Enric Palle, Ramotholo Sefako, Keivan G. Stassun, Thiam-Guan Tan, Andrew Vanderburg, George R. Ricker, David W. Latham, Roland Vanderspek, Sara Seager, Joshua N. Winn, Jon M Jenkins, Knicole Colon, Courtney Dressing, Sébastien Léepine, Philip S. Muirhead, Mark E. Rose, Joseph D Twicken, and Jesus Noel Villasenor
Subjects: Astronomy, Astrophysics
Abstract: We report the discovery of GJ 1252 b, a planet with a radius of 1.193 ± 0.074 R⊕ and an orbital period of 0.52 days around an M3-type star (0.381 ± 0.019 M⊕, 0.391 ± 0.020 R⊕) located 20.385 ± 0.019 pc away. We use Transiting Exoplanet Survey Satellite (TESS) data, ground-based photometry and spectroscopy, Gaia astrometry, and high angular resolution imaging to show that the transit signal seen in the TESS data must originate from a transiting planet. We do so by ruling out all false-positive scenarios that attempt to explain the transit signal as originating from an eclipsing stellar binary. Precise Doppler monitoring also leads to a tentative mass measurement of 2.09 ± 0.56 M⊕. The host star proximity, brightness (V = 12.19 mag, K = 7.92 mag), low stellar activity, and the system's short orbital period make this planet an attractive target for detailed characterization, including precise mass measurement, looking for other objects in the system, and planet atmosphere characterization.
Published: 2020
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6. Three Red Suns in the Sky: A Transiting, Terrestrial Planet in a Triple M-dwarf System at 6.9 pc

Author: Jennifer G. Winters, Amber A. Medina, Jonathan M. Irwin, David Charbonneau, Nicola Astudillo-Defru, Elliott P. Horch, Jason D. Eastman, Eliot Halley Vrijmoet, Todd J. Henry, Hannah Diamond-Lowe, Elaine Winston, Thomas Barclay, Xavier Bonfils, George R Ricker, Roland Vanderspek, David W. Latham, Sara Seager, Joshua N. Winn, Jon M Jenkins, Stéphane Udry, Joseph D Twicken, Johanna K. Teske, Peter Gregory Tenenbaum, Francesco Pepe, Felipe Murgas, Philip S. Muirhead, Jessica Mink, Christophe Lovis, Alan M. Levine, Sébastien Lépine, Wei-Chun Jao, Christopher E. Henze, Gábor Furész, Thierry Forveille, Pedro Figueira, Gilbert A. Esquerdo, Courtney D. Dressing, Rodrigo F. Díaz, Xavier Delfosse, Christopher J Burke, François Bouchy, Perry Berlind, and Jose-Manuel Almenara
Subjects: Astronomy
Abstract: We present the discovery from Transiting Exoplanet Survey Satellite (TESS) data of LTT 1445Ab. At a distance of 6.9 pc, it is the second nearest transiting exoplanet system found to date, and the closest one known for which the primary is an M dwarf. The host stellar system consists of three mid-to-late M dwarfs in a hierarchical configuration, which are blended in one TESS pixel. We use MEarth data and results from the Science Processing Operations Center data validation report to determine that the planet transits the primary star in the system. The planet has a radius of {1.38}_{-0.12}^{+0.13} {R}_{\oplus }, an orbital period of {5.35882}_{-0.00031}^{+0.00030} days, and an equilibrium temperature of {433}_{-27}^{+28} K. With radial velocities from the High Accuracy Radial Velocity Planet Searcher, we place a 3σ upper mass limit of 8.4 {M}_{\oplus } on the planet. LTT 1445Ab provides one of the best opportunities to date for the spectroscopic study of the atmosphere of a terrestrial world. We also present a detailed characterization of the host stellar system. We use high-resolution spectroscopy and imaging to rule out the presence of any other close stellar or brown dwarf companions. Nineteen years of photometric monitoring of A and BC indicate a moderate amount of variability, in agreement with that observed in the TESS light-curve data. We derive a preliminary astrometric orbit for the BC pair that reveals an edge-on and eccentric configuration. The presence of a transiting planet in this system hints that the entire system may be co-planar, implying that the system may have formed from the early fragmentation of an individual protostellar core.
Published: 2019
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7. Bright Opportunities for Atmospheric Characterization of Small Planets: Masses and Radii of K2-3 b, c, and d and GJ3470 b from Radial Velocity Measurements and Spitzer Transits

Author: Molly R. Kosiarek, Ian J. M. Crossfield, Kevin K. Hardegree-Ullman, John H. Livingston, Björn Benneke, Gregory W. Henry, Ward S. Howard, David Berardo, Sarah Blunt, Benjamin J. Fulton, Lea A. Hirsch, Andrew W. Howard, Howard Isaacson, Erik A. Petigura, Evan Sinukoff, Lauren Weiss, X. Bonfils, Courtney D. Dressing, Heather A. Knutson, Joshua E. Schlieder, Michael Werner, Varoujan Gorjian, Jessica Krick, Farisa Y. Morales, Nicola Astudillo-Defru, J.-M. Almenara, X. Delfosse, T. Forveille, C. Lovis, M. Mayor, F. Murgas, F. Pepe, N. C. Santos, S. Udry, H. T. Corbett, Octavi Fors, Nicholas M. Law, Jeffrey K. Ratzloff, and Daniel del Ser
Subjects: Astronomy, Astrophysics
Abstract: We report improved masses, radii, and densities for four planets in two bright M-dwarf systems, K2-3 and GJ3470, derived from a combination of new radial velocity and transit observations. Supplementing K2 photometry with follow-up Spitzer transit observations refined the transit ephemerides of K2-3 b, c, and d by over a factor of 10. We analyze ground-based photometry from the Evryscope and Fairborn Observatory to determine the characteristic stellar activity timescales for our Gaussian Process fit, including the stellar rotation period and activity region decay timescale. The stellar rotation signals for both stars are evident in the radial velocity data and is included in our fit using a Gaussian process trained on the photometry. We find the masses of K2-3 b, K2-3 c, and GJ3470 b to be 6.48(+0.99,-0.93), 2.14(+1.08,-1.28), and 12.58(+1.31,-1.28)Mꚛ, respectively. K2-3 d was not significantly detected and has a 3σ upper limit of 2.80 Mꚛ. These two systems are training cases for future TESS systems; due to the low planet densities (ρ < 3.7 g/cu.cm) and bright host stars (K < 9 mag), they are among the best candidates for transmission spectroscopy in order to characterize the atmospheric compositions of small planets.
Published: 2019
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8. A Second Planet Transiting LTT 1445A and a Determination of the Masses of Both Worlds

Author: Jennifer G. Winters, Ryan Cloutier, Amber A. Medina, Jonathan M. Irwin, David Charbonneau, Nicola Astudillo-Defru, Xavier Bonfils, Andrew W. Howard, Howard Isaacson, Jacob L. Bean, Andreas Seifahrt, Johanna K. Teske, Jason D. Eastman, Joseph D. Twicken, Karen A. Collins, Eric L. N. Jensen, Samuel N. Quinn, Matthew J. Payne, Martti H. Kristiansen, Alton Spencer, Andrew Vanderburg, Mathias Zechmeister, Lauren M. Weiss, Sharon Xuesong Wang, Gavin Wang, Stéphane Udry, Ivan A. Terentev, Julian Stürmer, Gudmundur Stefánsson, Avi Shporer, Stephen Shectman, Ramotholo Sefako, Hans Martin Schwengeler, Richard P. Schwarz, Nicholas Scarsdale, Ryan A. Rubenzahl, Arpita Roy, Lee J. Rosenthal, Paul Robertson, Erik A. Petigura, Francesco Pepe, Mark Omohundro, Joseph M. Akana Murphy, Felipe Murgas, Teo Močnik, Benjamin T. Montet, Ronald Mennickent, Andrew W. Mayo, Bob Massey, Jack Lubin, Christophe Lovis, Pablo Lewin, David Kasper, Stephen R. Kane, Jon M. Jenkins, Daniel Huber, Keith Horne, Michelle L. Hill, Paula Gorrini, Steven Giacalone, Benjamin Fulton, Thierry Forveille, Pedro Figueira, Tara Fetherolf, Courtney Dressing, Rodrigo F. Díaz, Xavier Delfosse, Paul A. Dalba, Fei Dai, C. C. Cortés, Ian J. M. Crossfield, Jeffrey D. Crane, Dennis M. Conti, Kevin I. Collins, Ashley Chontos, R. Paul Butler, Peyton Brown, Madison Brady, Aida Behmard, Corey Beard, Natalie M. Batalha, Jose-Manuel Almenara, Université du Québec à Rimouski (UQAR), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science
Subjects: STELLAR ACTIVITY, FOS: Physical sciences, SUPER-EARTH, Astrophysics::Cosmology and Extragalactic Astrophysics, EARTH-SIZED PLANET, HARPS, NEARBY, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, QC, TERRESTRIAL PLANET, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QB, MCC, Earth and Planetary Astrophysics (astro-ph.EP), RADIAL-VELOCITIES, ERROR-CORRECTION, M DWARFS, Astronomy and Astrophysics, 3rd-DAS, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], SYSTEM, Astrophysics - Earth and Planetary Astrophysics
Abstract: LTT 1445 is a hierarchical triple M-dwarf star system located at a distance of 6.86 parsecs. The primary star LTT 1445A (0.257 M_Sun) is known to host the transiting planet LTT 1445Ab with an orbital period of 5.4 days, making it the second closest known transiting exoplanet system, and the closest one for which the host is an M dwarf. Using TESS data, we present the discovery of a second planet in the LTT 1445 system, with an orbital period of 3.1 days. We combine radial velocity measurements obtained from the five spectrographs ESPRESSO, HARPS, HIRES, MAROON-X, and PFS to establish that the new world also orbits LTT 1445A. We determine the mass and radius of LTT 1445Ab to be 2.87+/-0.25 M_Earth and 1.304^{+0.067}_{-0.060} R_Earth, consistent with an Earth-like composition. For the newly discovered LTT 1445Ac, we measure a mass of 1.54^{+0.20}_{-0.19} M_Earth and a minimum radius of 1.15 R_Earth, but we cannot determine the radius directly as the signal-to-noise of our light curve permits both grazing and non-grazing configurations. Using MEarth photometry and ground-based spectroscopy, we establish that star C (0.161 M_Sun) is likely the source of the 1.4-day rotation period, and star B (0.215 M_Sun) has a likely rotation period of 6.7 days. We estimate a probable rotation period of 85 days for LTT 1445A. Thus, this triple M-dwarf system appears to be in a special evolutionary stage where the most massive M dwarf has spun down, the intermediate mass M dwarf is in the process of spinning down, while the least massive stellar component has not yet begun to spin down., Comment: Accepted to the Astronomical Journal. 4 tables, 10 figures; RV table available upon request
Published: 2022
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9. The LHS 1678 system : two earth-sized transiting planets and an astrometric companion orbiting an M dwarf near the convective boundary at 20 pc

Author: Michele L. Silverstein, Joshua E. Schlieder, Thomas Barclay, Benjamin J. Hord, Wei-Chun Jao, Eliot Halley Vrijmoet, Todd J. Henry, Ryan Cloutier, Veselin B. Kostov, Ethan Kruse, Jennifer G. Winters, Jonathan M. Irwin, Stephen R. Kane, Keivan G. Stassun, Chelsea Huang, Michelle Kunimoto, Evan Tey, Andrew Vanderburg, Nicola Astudillo-Defru, Xavier Bonfils, C. E. Brasseur, David Charbonneau, David R. Ciardi, Karen A. Collins, Kevin I. Collins, Dennis M. Conti, Ian J. M. Crossfield, Tansu Daylan, John P. Doty, Courtney D. Dressing, Emily A. Gilbert, Keith Horne, Jon M. Jenkins, David W. Latham, Andrew W. Mann, Elisabeth Matthews, Leonardo A. Paredes, Samuel N. Quinn, George R. Ricker, Richard P. Schwarz, Sara Seager, Ramotholo Sefako, Avi Shporer, Jeffrey C. Smith, Christopher Stockdale, Thiam-Guan Tan, Guillermo Torres, Joseph D. Twicken, Roland Vanderspek, Gavin Wang, Joshua N. Winn, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Bonfils, Xavier, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), University of Washington [Seattle], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)
Subjects: FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, M dwarf stars, NCAD, Astrophysics::Solar and Stellar Astrophysics, QB Astronomy, Exoplanet systems, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, QC, QB, Earth and Planetary Astrophysics (astro-ph.EP), MCC, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, 3rd-DAS, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Low mass stars, Transit photometry, Astrometric binary stars, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], [PHYS.ASTR] Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the TESS discovery of the LHS 1678 (TOI-696) exoplanet system, comprised of two approximately Earth-sized transiting planets and a likely astrometric brown dwarf orbiting a bright ($V_J$=12.5, $K_s$=8.3) M2 dwarf at 19.9 pc. The two TESS-detected planets are of radius 0.70$\pm$0.04 $R_\oplus$ and 0.98$\pm$0.06 $R_\oplus$ in 0.86-day and 3.69-day orbits, respectively. Both planets are validated and characterized via ground-based follow-up observations. HARPS RV monitoring yields 97.7 percentile mass upper limits of 0.35 $M_\oplus$ and 1.4 $M_\oplus$ for planets b and c, respectively. The astrometric companion detected by the CTIO/SMARTS 0.9m has an orbital period on the order of decades and is undetected by other means. Additional ground-based observations constrain the companion to being a high-mass brown dwarf or smaller. Each planet is of unique interest; the inner planet has an ultra-short period, and the outer planet is in the Venus zone. Both are promising targets for atmospheric characterization with the JWST and mass measurements via extreme-precision radial velocity. A third planet candidate of radius 0.9$\pm$0.1 $R_\oplus$ in a 4.97-day orbit is also identified in multi-Cycle TESS data for validation in future work. The host star is associated with an observed gap in the lower main sequence of the Hertzsprung-Russell diagram. This gap is tied to the transition from partially- to fully-convective interiors in M dwarfs, and the effect of the associated stellar astrophysics on exoplanet evolution is currently unknown. The culmination of these system properties makes LHS 1678 a unique, compelling playground for comparative exoplanet science and understanding the formation and evolution of small, short-period exoplanets orbiting low-mass stars., Published in The Astronomical Journal (31 pages, 21 figures, 11 tables, 3 appendices)
Published: 2022

10. Line-by-line velocity measurements, an outlier-resistant method for precision velocimetry

Author: Étienne Artigau, Charles Cadieux, Neil J. Cook, René Doyon, Thomas Vandal, Jean-François Donati, Claire Moutou, Xavier Delfosse, Pascal Fouqué, Eder Martioli, François Bouchy, Jasmine Parsons, Andres Carmona, Xavier Dumusque, Nicola Astudillo-Defru, Xavier Bonfils, Lucille Mignon, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract: We present a new algorithm for precision radial velocity (pRV) measurements, a line-by-line (LBL) approach designed to handle outlying spectral information in a simple but efficient manner. The effectiveness of the LBL method is demonstrated on two datasets, one obtained with SPIRou on Barnard's star, and the other with HARPS on Proxima Centauri. In the near-infrared, the LBL provides a framework for m/s-level accuracy in pRV measurements despite the challenges associated with telluric absorption and sky emission lines. We confirm with SPIRou measurements spanning 2.7 years that the candidate super-Earth on a 233-day orbit around Barnard's star is an artifact due to a combination of time-sampling and activity. The LBL analysis of the Proxima Centauri HARPS post-upgrade data alone easily recovers the Proxima b signal and also provides a 2-sigma detection of the recently confirmed 5-day Proxima d planet, but argues against the presence of the candidate Proxima c with a period of 1900 days. We provide evidence that the Proxima c signal is associated with small, unaccounted systematic effects affecting the HARPS-TERRA template matching RV extraction method for long-period signals. Finally, the LBL framework provides a very effective activity indicator, akin to the full width at half maximum derived from the cross-correlation function, from which we infer a rotation period of $92.1^{+4.2}_{-3.5}$ days for Proxima., Accepted for publication in AJ
Published: 2022
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11. HD 207897 b:A dense sub-Neptune transiting a nearby and bright K-type star

Author: Andrew W. Mayo, Jorge Lillo-Box, George R. Ricker, C. Moutou, Stephen R. Kane, René Tronsgaard, Ashley Chontos, Allyson Bieryla, Karen A. Collins, Nicola Astudillo-Defru, Luc Arnold, Rafael Luque, Andrew W. Howard, Xavier Dumusque, S. G. Sousa, V. Bourrier, Erik Petigura, Joshua N. Winn, Magali Deleuil, Lauren M. Weiss, Enric Palle, Nuno C. Santos, Steven Giacalone, J. Rey, Damien Ségransan, Courtney D. Dressing, Paul A. Dalba, Arpita Roy, Jack Lubin, Sara Seager, Corey Beard, Natalie M. Batalha, Daniel Huber, C. E. Brasseur, T. Lopez, Howard Isaacson, Teo Mocnik, Jason D. Eastman, Peter Tenenbaum, N. Heidari, Michelle L. Hill, P. Cortés-Zuleta, O. Mousis, E. Delgado Mena, Diana Dragomir, D. W. Latham, François Bouchy, Aida Behmard, David Ehrenreich, P. A. Strøm, Fei Dai, F. Vakili, T. Forveille, Tansu Daylan, R. Vanderspek, Keivan G. Stassun, Alexandre Santerne, Melissa J. Hobson, X. Bonfils, Benjamin J. Fulton, G. Montagnier, M. Stalport, Francesco Pepe, Lars A. Buchhave, Flavien Kiefer, Nicholas Scarsdale, Lee J. Rosenthal, Vardan Adibekyan, Paul Robertson, Olivier Demangeon, J. M. Jenkins, A. Carmona, Nematollah Riazi, Stéphane Udry, Rodrigo F. Díaz, N. C. Hara, G. Gaisne, Thomas Barclay, Tara Fetherolf, X. Delfosse, L. Mignon, Sergio Hoyer, B. Courcol, J. Orell-Mique, S. Borgniet, Guillaume Hébrard, Ryan A. Rubenzahl, Lea A. Hirsch, S. Dalal, Ian J. M. Crossfield, Joseph M. Akana Murphy, L. Acuna, Isabelle Boisse, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Geneva Observatory, Université de Genève = University of Geneva (UNIGE), European Southern Observatory (ESO), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), University of St Andrews [Scotland], Faculdade de Ciências [Lisboa], Universidade de Lisboa = University of Lisbon (ULISBOA), SwRI Planetary Science Directorate [Boulder], Southwest Research Institute [Boulder] (SwRI), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, NASA Ames Research Center Cooperative for Research in Earth Science in Technology (ARC-CREST), NASA Ames Research Center (ARC), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Observatoire Astronomique de l'Université de Genève (ObsGE), National Space Institute [Lyngby] (DTU Space), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), SETI Institute, Instituto de Astrofísica e Ciências do Espaço (IASTRO), MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology (MIT), Department of Astronomy, University of California, Genome Sequencing Center, University of Washington School of Medicine, Universidad de Chile = University of Chile [Santiago] (UCHILE), Departamento de Quimica Inorganica e Ingenieria Quimica (Cordoba, Spain), Universidad de Córdoba = University of Córdoba [Córdoba], Peoples Friendship University of Russia [RUDN University] (RUDN), Center for Astrophysics (emeritus), Harvard-Smithsonian, Cambridge, MA, USA, Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Didactique André Revuz (LDAR (EA_4434)), Université d'Artois (UA)-Université Paris Diderot - Paris 7 (UPD7)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Instituto de Astrofisica de Canarias (IAC), Universidad de La Laguna [Tenerife - SP] (ULL), Vanderbilt University [Nashville], SLAC National Accelerator Laboratory (SLAC), Stanford University, Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Peyton Hall, Clarient Pathology Services, Partenaires INRAE, Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), University of Geneva [Switzerland], Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto = University of Porto, Instituto de Astronomía y Física del Espacio [Buenos Aires] (IAFE), Consejo Nacional de Investigaciones Científicas y Técnicas [Buenos Aires] (CONICET)-Universidad de Buenos Aires [Buenos Aires] (UBA), IFP Energies nouvelles (IFPEN), Center for Space Research [Cambridge] (CSR), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and ANR-18-CE31-0019,SPlaSH,Recherche de planètes habitables avec SPIRou(2018)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 010308 nuclear & particles physics, Population, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Radius, Planetary system, Star (graph theory), 01 natural sciences, Exoplanet, Radial velocity, 13. Climate action, Space and Planetary Science, Planet, Neptune, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], education, 010303 astronomy & astrophysics, QB, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the discovery and characterization of a transiting sub-Neptune orbiting with a 16.20 day period around a nearby (28 pc) and bright(V=8.37) K0V star HD207897 (TOI-1611). This discovery is based on photometric measurements from the Transiting Exoplanet Survey Satellite(TESS) mission and radial velocity (RV) observations from the SOPHIE, Automated Planet Finder (APF) and HIRES high precision spectrographs. We used EXOFASTv2 for simultaneously modeling the parameters of the planet and its host star, combining photometric and RV data to determine the planetary system parameters. We show that the planet has a radius of 2.50+/-0.08 RE and a mass of either 14.4+/-1.6 ME or 15.9+/-1.6 ME with nearly equal probability; the two solutions correspond to two possibilities for the stellar activity period. Hence, the density is either 5.1+/-0.7 g cm^-3 or 5.5^{+0.8}_{-0.7} g cm^-3, making it one of the relatively rare dense sub-Neptunes. The existence of such a dense planet at only 0.12 AU from its host star is unusual in the currently observed sub-Neptune (2, Comment: 18 pages, 12 figures, 6 tables; accepted for publication in the A&A journal; comments welcome
Published: 2022
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12. GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star

Author: Jeffrey C. Smith, Philipp Eigmüller, Edward H. Morgan, Sebastiano Padovan, Massimiliano Esposito, Felipe Murgas, Robert L. Morris, Jessie L. Christiansen, Jan Subjak, Alexander Chaushev, Rafael Luque, William D. Cochran, Iskra Georgieva, Nuno C. Santos, Enric Palle, Damien Ségransan, Malcolm Fridlund, George R. Ricker, René Doyon, Priyanka Chaturvedi, Samuel N. Quinn, Vincent Van Eylen, Judith Korth, Marshall C. Johnson, Guillaume Gaisné, Hannah L. M. Osborne, Michel Mayor, Eike W. Guenther, Pablo Lewin, Joshua E. Schlieder, Norio Narita, Oscar Barragán, Etienne Artigau, Thierry Forveille, Roland Vanderspek, Joshua N. Winn, Simon Albrecht, Artie P. Hatzes, Juan Cabrera, E. Goffo, Jack J. Lissauer, Steve B. Howell, P. Figueira, José R. De Meideiros, Joseph D. Twicken, David Charbonneau, Szilard Csizmadia, Savita Mathur, Alexis M. S. Smith, Seth Redfield, Sascha Grziwa, Luisa M. Serrano, Xavier Delfosse, Rodrigo F. Díaz, Fei Dai, Rafael A. García, Stéphane Udry, Jon M. Jenkins, Petr Kabath, Emil Knudstrup, Kristine W F Lam, Francesco Pepe, François Bouchy, Coel Hellier, Carina M. Persson, Davide Gandolfi, Jose M Almenara, Sara Seager, Karen A. Collins, Nicola Astudillo-Defru, Heike Rauer, David W. Latham, Teruyuki Hirano, Michael Vezie, John H. Livingston, Claudio Melo, Christophe Lovis, and X. Bonfils
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Multidisciplinary, Red dwarf, Astronomy, ASTRONOMY, FOS: Physical sciences, Star (graph theory), Sub-Earth, Planet, QB460, Period (geology), Astrophysics::Solar and Stellar Astrophysics, PLANET SCI, Astrophysics::Earth and Planetary Astrophysics, Geology, QB600, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics, QB, QB799
Abstract: Ultra-short-period (USP) exoplanets have orbital periods shorter than one day. Precise masses and radii of USPs could provide constraints on their unknown formation and evolution processes. We report the detection and characterization of the USP planet GJ 367b using high precision photometry and radial velocity observations. GJ 367b orbits a bright (V-band magnitude = 10.2), nearby, red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of $0.718 \pm 0.054$ Earth-radii, a mass of $0.546 \pm 0.078$ Earth-masses, making it a sub-Earth. The corresponding bulk density is $8.106 \pm 2.165$ g cm$^-3$, close to that of iron. An interior structure model predicts the planet has an iron core radius fraction of $86 \pm 5\%$, similar to Mercury's interior., Comment: Note: "This is the author's version of the work. It is posted here by permission of the AAAS for personal use, not for redistribution. The definitive version was published in Science , (2021-12-03), doi: 10.1126/science.aay3253"
Published: 2021

13. A More Precise Mass for GJ 1214 b and the Frequency of Multiplanet Systems Around Mid-M Dwarfs

Author: David Charbonneau, Nicola Astudillo-Defru, R. Cloutier, Drake Deming, Xavier Bonfils, University of Maryland [College Park], University of Maryland System, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), and Universidad Católica de la Santísima Concepción (UCSC)
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, 01 natural sciences, Exoplanet, Radial velocity, Space and Planetary Science, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present an intensive effort to refine the mass and orbit of the enveloped terrestrial planet GJ 1214 b using 165 radial velocity (RV) measurements taken with the HARPS spectrograph over a period of ten years. We conduct a joint analysis of the RVs with archival Spitzer/IRAC transits and measure a planetary mass and radius of $8.17\pm 0.43 M_{\oplus}$ and $2.742^{+0.050}_{-0.053} R_{\oplus}$. Assuming GJ 1214 b is an Earth-like core surrounded by a H/He envelope, we measure an envelope mass fraction of $X_{\rm env}= 5.24^{+0.30}_{-0.29}$%. GJ 1214 b remains a prime target for secondary eclipse observations of an enveloped terrestrial, the scheduling of which benefits from our tight constraint on the orbital eccentricity of $, Accepted for publication in AAS journals. 16 pages (main) + 16 pages (appendices), 9 figures (main) + 24 figures (appendix B). Two additional figures in appendix B could not be included due to compilation errors. These figures are included in the source files
Published: 2021
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14. Masses and compositions of three small planets orbiting the nearby M dwarf L231-32 (TOI-270) and the M dwarf radius valley

Author: V. Van Eylen, M. Esposito, D. A. Caldwell, Sara Seager, David Charbonneau, M. R. Zapatero Osorio, René Doyon, K. W. F. Lam, J. R. De Medeiros, Xavier Bonfils, Carina M. Persson, Nuno C. Santos, Judith Korth, A. Suárez Mascareño, Fei Dai, Teriyuki Hirano, C. Lovis, Enric Palle, Norio Narita, Francesco Pepe, A. P. Hatzes, Jon M. Jenkins, Hannah L. M. Osborne, Anders Bo Justesen, Nicola Astudillo-Defru, Thomas Mikal-Evans, Felipe Murgas, J. Cabrera, Iskra Georgieva, Davide Gandolfi, Savita Mathur, Grzegorz Nowak, Gábor Fűrész, E. Goffo, X. Delfosse, Eike W. Guenther, David W. Latham, François Bouchy, Baptiste Lavie, Rodrigo F. Díaz, Étienne Artigau, C. S. K. Ho, Ronald E. Mennickent, Stéphane Udry, Petr Kabath, John H. Livingston, T. Forveille, Roland Vanderspek, George R. Ricker, James E. Owen, Seth Redfield, J. D. Twicken, B. Campos Estrada, J. Šubjak, William D. Cochran, Mario Damasso, Daniel Foreman-Mackey, Simon Albrecht, S. Grziwa, Jose-Manuel Almenara, Joshua N. Winn, Susan E. Mullally, L. M. Serrano, P. Figueira, Alexis M. S. Smith, M. Fridlund, Oscar Barragán, S. C. C. Barros, Rafael Luque, Szilard Csizmadia, Emil Knudstrup, Priyanka Chaturvedi, University College of London [London] (UCL), Universidad de Concepción [Chile], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Children's Hospital of Leeds, Department of Neurosurgery, Tohoku University School of Medicine, Universidad de Córdoba [Cordoba], University of Warwick [Coventry], Department of Brain and Behavioural Sciences, University of Pavia, The Royal Society, and Commission of the European Communities
Subjects: Fundamental Parameters, 010504 meteorology & atmospheric sciences, planets and satellites: individual, Formation, Astrophysics, 01 natural sciences, Planet, planets and satellites: formation, Astrophysics::Solar and Stellar Astrophysics, composition [planets and satellites], 10. No inequality, planets and satellites: fundamental parameters, 010303 astronomy & astrophysics, individual: L231-32 [planets and satellites], Physics, Earth and Planetary Astrophysics (astro-ph.EP), STAR, planets and satellites: composition, Planets and Satellites, formation [planets and satellites], Radius, Orbital period, Photoevaporation, Exoplanet, Radial velocity, EVAPORATION, Astrophysics - Solar and Stellar Astrophysics, Physical Sciences, Astrophysics::Earth and Planetary Astrophysics, Composition, EXOPLANET, Outer planets, KEPLER, FOS: Physical sciences, Context (language use), Individual, SUPER-EARTH, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, planets and satellites: individual: L231-32, fundamental parameters [planets and satellites], SEARCH, 0103 physical sciences, 0201 Astronomical and Space Sciences, SURFACE ROTATION, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Science & Technology, ERROR-CORRECTION, Astronomy and Astrophysics, VELOCITY, STELLAR, 13. Climate action, Space and Planetary Science, L231-32, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We report on precise Doppler measurements of L231-32 (TOI-270), a nearby M dwarf ($d=22$ pc, $M_\star = 0.39$ M$_\odot$, $R_\star = 0.38$ R$_\odot$), which hosts three transiting planets that were recently discovered using data from the Transiting Exoplanet Survey Satellite (TESS). The three planets are 1.2, 2.4, and 2.1 times the size of Earth and have orbital periods of 3.4, 5.7, and 11.4 days. We obtained 29 high-resolution optical spectra with the newly commissioned Echelle Spectrograph for Rocky Exoplanet and Stable Spectroscopic Observations (ESPRESSO) and 58 spectra using the High Accuracy Radial velocity Planet Searcher (HARPS). From these observations, we find the masses of the planets to be $1.58 \pm 0.26$, $6.15 \pm 0.37$, and $4.78 \pm 0.43$ M$_\oplus$, respectively. The combination of radius and mass measurements suggests that the innermost planet has a rocky composition similar to that of Earth, while the outer two planets have lower densities. Thus, the inner planet and the outer planets are on opposite sides of the `radius valley' -- a region in the radius-period diagram with relatively few members, which has been interpreted as a consequence of atmospheric photo-evaporation. We place these findings into the context of other small close-in planets orbiting M dwarf stars, and use support vector machines to determine the location and slope of the M dwarf ($T_\mathrm{eff} < 4000$ K) radius valley as a function of orbital period. We compare the location of the M dwarf radius valley to the radius valley observed for FGK stars, and find that its location is a good match to photo-evaporation and core-powered mass loss models. Finally, we show that planets below the M dwarf radius valley have compositions consistent with stripped rocky cores, whereas most planets above have a lower density consistent with the presence of a H-He atmosphere., Accepted for publication in MNRAS
Published: 2021
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15. TOI-674b: An oasis in the desert of exo-Neptunes transiting a nearby M dwarf

Author: Xavier Bonfils, Michael W. Werner, Nicola Astudillo-Defru, Jon M. Jenkins, George R. Ricker, Ian J. M. Crossfield, Eric L. N. Jensen, David R. Ciardi, Emmanuel Jehin, Judith Korth, David W. Latham, Farisa Y. Morales, Ismael Mireles, Keivan G. Stassun, Étienne Artigau, Rodrigo F. Díaz, J. Orell-Miquel, Pedro Figueira, Stéphane Udry, René Doyon, X. Delfosse, Jack J. Lissauer, Francesco Pepe, Damien Ségransan, Nuno C. Santos, Christophe Lovis, Peter Tenenbaum, Elisa V. Quintana, Björn Benneke, Rachel A. Matson, Jose-Manuel Almenara, Felipe Murgas, Douglas A. Caldwell, Kevin I. Collins, Phil Evans, C. E. Brasseur, Stephen R. Kane, François Bouchy, David Charbonneau, G. Morello, Roland Vanderspek, Charles Beichman, Elisabeth Matthews, T. Forveille, Khalid Barkaoui, Sara Seager, Diana Dragomir, Erica J. Gonzales, Robert F. Goeke, G. Gaisne, Joshua E. Schlieder, John H. Livingston, Natalia Guerrero, Claudio Melo, Alan M. Levine, Joshua N. Winn, Steve B. Howell, Michaël Gillon, Francisco J. Pozuelos, Jason D. Eastman, Varoujan Gorjian, Karen A. Collins, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), and Children's Hospital of Leeds
Subjects: 010504 meteorology & atmospheric sciences, GASEOUS PLANETS [PLANETS AND SATELLITES], FOS: Physical sciences, RADIAL VELOCITIES [TECHNIQUES], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, purl.org/becyt/ford/1 [https], Planet, 0103 physical sciences, GENERAL [PLANETS AND SATELLITES], PLANETARY SYSTEMS, 010303 astronomy & astrophysics, INDIVIDUAL: TOI-674 [STARS], Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Orbital elements, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Radius, purl.org/becyt/ford/1.3 [https], PHOTOMETRIC [TECHNIQUES], Light curve, Orbital period, Exoplanet, Radial velocity, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Planetary mass, Astrophysics - Earth and Planetary Astrophysics
Abstract: We use TESS, Spitzer, ground-based light curves and HARPS spectrograph radial velocity measurements to establish the physical properties of the transiting exoplanet candidate TOI-674b. We perform a joint fit of the light curves and radial velocity time series to measure the mass, radius, and orbital parameters of the candidate. We confirm and characterize TOI-674b, a low-density super-Neptune transiting a nearby M dwarf. The host star (TIC 158588995, $V = 14.2$ mag, $J = 10.3$ mag) is characterized by its M2V spectral type with $\mathrm{M}_\star=0.420\pm 0.010$ M$_\odot$, $\mathrm{R}_\star = 0.420\pm 0.013$ R$_\odot$, and $\mathrm{T}_{\mathrm{eff}} = 3514\pm 57$ K, and is located at a distance $d=46.16 \pm 0.03$ pc. Combining the available transit light curves plus radial velocity measurements and jointly fitting a circular orbit model, we find an orbital period of $1.977143 \pm 3\times 10^{-6}$ days, a planetary radius of $5.25 \pm 0.17$ $\mathrm{R}_\oplus$, and a mass of $23.6 \pm 3.3$ $\mathrm{M}_\oplus$ implying a mean density of $\rho_\mathrm{p} = 0.91 \pm 0.15$ [g cm$^{-3}$]. A non-circular orbit model fit delivers similar planetary mass and radius values within the uncertainties. Given the measured planetary radius and mass, TOI-674b is one of the largest and most massive super-Neptune class planets discovered around an M type star to date. It is also a resident of the so-called Neptunian desert and a promising candidate for atmospheric characterisation using the James Webb Space Telescope., Comment: 22 pages, 16 figures. Accepted for publication in A&A
Published: 2021
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16. The SOPHIE search for northern extrasolar planets. XVII. A wealth of new objects: Six cool Jupiters, three brown dwarfs, and 16 low-mass binary stars

Author: J. Rey, M. J. Hobson, C. Lovis, Vincent Bourrier, Magali Deleuil, N. Heidari, O. Mousis, Flavien Kiefer, S. Dalal, C. Moutou, Eder Martioli, P. Cortés-Zuleta, Nicola Astudillo-Defru, Johannes Sahlmann, Luc Arnold, Isabelle Boisse, L. Mignon, François Bouchy, Olivier Demangeon, Alexandre Santerne, Xavier Bonfils, Nathan Hara, Guillaume Hébrard, Rodrigo F. Díaz, Stéphane Udry, Nuno C. Santos, Damien Ségransan, X. Delfosse, T. Forveille, T. Lopez, S. G. Sousa, B. Brugger, P. A. Strøm, Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and ANR-18-CE31-0019,SPlaSH,Recherche de planètes habitables avec SPIRou(2018)
Subjects: 010504 meteorology & atmospheric sciences, BROWN DWARFS, SPECTROGRAPHS [INSTRUMENTATION], Brown dwarf, FOS: Physical sciences, RADIAL VELOCITIES [TECHNIQUES], Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, purl.org/becyt/ford/1 [https], ASTROMETRY, Planet, 0103 physical sciences, Binary star, PLANETARY SYSTEMS, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Giant planet, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Planetary system, Exoplanet, Radial velocity, Stars, Astrophysics - Solar and Stellar Astrophysics, LOW-MASS [STARS], 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Distinguishing classes within substellar objects and understanding their formation and evolution need larger samples of substellar companions such as exoplanets, brown dwarfs, and low-mass stars. In this paper, we look for substellar companions using radial velocity surveys of FGK stars with the SOPHIE spectrograph at the Observatoire de Haute-Provence. We assign here the radial velocity variations of 27 stars to their orbital motion induced by low-mass companions. We also constrained their plane-of-the-sky motion using HIPPARCOS and Gaia Data Release 1 measurements, which constrain the true masses of some of these companions. We report the detection and characterization of six cool Jupiters, three brown dwarf candidates, and 16 low-mass stellar companions. We additionally update the orbital parameters of the low-mass star HD 8291 B, and we conclude that the radial velocity variations of HD 204277 are likely due to stellar activity despite resembling the signal of a giant planet. One of the new giant planets, BD+631405 b, adds to the population of highly eccentric cool Jupiters, and it is presently the most massive member. Two of the cool Jupiter systems also exhibit signatures of an additional outer companion. The orbital periods of the new companions span 30 days to 11.5 years, their masses 0.72 Jupiter mass to 0.61 Solar mass, and their eccentricities 0.04 to 0.88. These discoveries probe the diversity of substellar objects and low-mass stars, which will help constrain the models of their formation and evolution., Comment: 27 pages, 14 figures, 13 tables, Accepted in A&A
Published: 2021
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17. TOI-269 b: an eccentric sub-Neptune transiting a M2 dwarf revisited with ExTrA

Author: Sara Seager, Eric B. Ting, Felipe Murgas, Nicholas M. Law, D. Maurel, S. Curaba, Tianjun Gan, S. Rochat, Richard G. West, George R. Ricker, Francesco Pepe, René Doyon, P. Kern, Coel Hellier, Jon M. Jenkins, Thibaut Moulin, I. C. Leão, G. Gaisne, Caroline Dorn, Xavier Bonfils, Laurent Jocou, Yves Magnard, J.-J. Correia, Eric Stadler, P. Rabou, C. Melo, Joshua N. Winn, C. Ziegler, J. D. Twicken, C. Lovis, Karen A. Collins, Nicola Astudillo-Defru, B. L. Canto Martins, Aurélien Wyttenbach, X. Delfosse, Alain Roux, Kevin I. Collins, Alain Delboulbé, J. F. Otegi, David R. Anderson, Jose-Manuel Almenara, William Waalkes, Ravit Helled, Marion Cointepas, François Bouchy, J. R. De Medeiros, Roland Vanderspek, Étienne Artigau, David Charbonneau, Pedro Figueira, T. Forveille, David W. Latham, L. Gluck, David R. Rodriguez, Andrew W. Mann, A. Wunsche, S. Lafrasse, Nuno C. Santos, Damien Ségransan, Rodrigo F. Díaz, Stéphane Udry, Philippe Feautrier, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), and Université de Montréal (UdeM)
Subjects: 010504 meteorology & atmospheric sciences, media_common.quotation_subject, FOS: Physical sciences, Astrophysics, 01 natural sciences, Transmission spectroscopy, Photometry (optics), Neptune, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Eccentricity (behavior), Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, media_common, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astronomy and Astrophysics, Radius, Orbital period, Exoplanet, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the confirmation of a new sub-Neptune close to the transition between super-Earths and sub-Neptunes transiting the M2 dwarf TOI- 269 (TIC 220479565, V = 14.4 mag, J = 10.9 mag, Rstar = 0.40 Rsun, Mstar = 0.39 Msun, d = 57 pc). The exoplanet candidate has been identified in multiple TESS sectors, and validated with high-precision spectroscopy from HARPS and ground-based photometric follow-up from ExTrA and LCO-CTIO. We determined mass, radius, and bulk density of the exoplanet by jointly modeling both photometry and radial velocities with juliet. The transiting exoplanet has an orbital period of P = 3.6977104 +- 0.0000037 days, a radius of 2.77 +- 0.12 Rearth, and a mass of 8.8 +- 1.4 Mearth. Since TOI-269 b lies among the best targets of its category for atmospheric characterization, it would be interesting to probe the atmosphere of this exoplanet with transmission spectroscopy in order to compare it to other sub-Neptunes. With an eccentricity e = 0.425+0.082-0.086, TOI-269 b has one of the highest eccentricities of the exoplanets with periods less than 10 days. The star being likely a few Gyr old, this system does not appear to be dynamically young. We surmise TOI-269 b may have acquired its high eccentricity as it migrated inward through planet-planet interactions., Comment: 23 pages, 16 figures, Accepted for publication in A&A
Published: 2021
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18. The SOPHIE search for northern extrasolar planets: XVIII. Six new cold jupiters including one of the most eccentric exoplanet orbits

Author: Nathan Hara, M. J. Hobson, João P. Faria, Alexandre Santerne, Stéphane Udry, Vincent Bourrier, X. Delfosse, François Bouchy, Rodrigo F. Díaz, J. D. Camacho, Guillaume Hébrard, Olivier Demangeon, Xavier Bonfils, Tiago L. Campante, T. Lopez, Isabelle Boisse, S. Dalal, Flavien Kiefer, Susana Sousa, Nuno C. Santos, C. Moutou, T. Forveille, Luc Arnold, J. Rey, Benard Nsamba, Maria Tsantaki, P. A. Strøm, Johannes Sahlmann, Magali Deleuil, Nicola Astudillo-Defru, and N. Heidari
Subjects: 010504 meteorology & atmospheric sciences, Gas giant, Population, FOS: Physical sciences, Context (language use), RADIAL VELOCITIES [TECHNIQUES], Astrophysics, 01 natural sciences, Jupiter, purl.org/becyt/ford/1 [https], Planet, 0103 physical sciences, DETECTION [PLANETS AND SATELLITES], Transit (astronomy), education, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, education.field_of_study, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Exoplanet, Radial velocity, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. Due to their low transit probability, the long-period planets are, as a population, only partially probed by transit surveys. Radial velocity surveys thus have a key role to play, in particular for giant planets. Cold Jupiters induce a typical radial velocity semi-amplitude of 10m.s^{-1}, which is well within the reach of multiple instruments that have now been in operation for more than a decade. Aims. We take advantage of the ongoing radial velocity survey with the sophie high-resolution spectrograph, which continues the search started by its predecessor elodie to further characterize the cold Jupiter population. Methods. Analyzing the radial velocity data from six bright solar-like stars taken over a period of up to 15 years, we attempt the detection and confirmation of Keplerian signals. Results. We announce the discovery of six planets, one per system, with minimum masses in the range 2.99-8.3 Mjup and orbital periods between 200 days and 10 years. The data do not provide enough evidence to support the presence of additional planets in any of these systems. The analysis of stellar activity indicators confirms the planetary nature of the detected signals. Conclusions. These six planets belong to the cold and massive Jupiter population, and four of them populate its eccentric tail. In this respect, HD 80869 b stands out as having one of the most eccentric orbits, with an eccentricity of 0.862^{+0.028}_{-0.018}. These planets can thus help to better constrain the migration and evolution processes at play in the gas giant population. Furthermore, recent works presenting the correlation between small planets and cold Jupiters indicate that these systems are good candidates to search for small inner planets., 24 pages, 12 figures, Accepted for publication in Astronomy & Astrophysics
Published: 2021
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19. Planetary system LHS 1140 revisited with ESPRESSO and TESS

Author: L. Acuña, Nathan Hara, Nuno C. Santos, David Barrado, João P. Faria, Emmanuel Marcq, Nicola Astudillo-Defru, Stéphane Udry, Xavier Bonfils, Francesco Pepe, Pedro Figueira, A. Leleu, Philippe Robutel, Alexandre C. M. Correia, Jorge Lillo-Box, S. G. Sousa, C. Lovis, Magali Deleuil, O. Mousis, Jose-Manuel Almenara, Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Instituto de Astrofísica e Ciências do Espaço (IASTRO), Center for Space and Habitability (CSH), University of Bern, Space Research and Planetary Sciences [Bern) (WP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], National Centre of Competence in Research PlanetS (NCCR PlanetS), Universität Bern [Bern]-Universität Bern [Bern]-Swiss National Science Foundation (SNSF), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Departamento de Física e Astronomia [Porto] (DFA/FCUP), Faculdade de Ciências da Universidade do Porto (FCUP), Universidade do Porto-Universidade do Porto, Geneva Observatory, University of Geneva [Switzerland], Centro de Física da Universidade de Coimbra (CFisUC), Universidade de Coimbra [Coimbra], Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Spanish StateResearch Agency (AEI) Projects No.ESP2017-87676-C5-1-R and No. MDM-2017-0737 Unidad de Excelencia 'María de Maeztu' – Centro de Astrobiología(INTA-CSIC). This work was supported by FCT – Fundação para a Ciênciae a Tecnologia through national funds and by FEDER through COM-PETE2020 – Programa Operacional Competitividade e Internacionalizaçãoby these grants: UID/FIS/04434/2019, UIDB/04434/2020, UIDP/04434/2020, PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER-032113, PTDC/FIS-AST/28953/2017 & POCI-01-0145-FEDER-028953. N.A.-D. acknowledges thesupport of FONDECYT project 3180063. X.B. and J.M.A. acknowledge fundingfrom the European Research Council under the ERC Grant Agreement n. 337591-ExTrA. A.C. acknowledges support by CFisUC projects (UIDB/04564/2020and UIDP/04564/2020), ENGAGE SKA (POCI-01-0145-FEDER-022217), andPHOBOS (POCI-01-0145-FEDER-029932), funded by COMPETE 2020 andFCT, Portugal. J.P.F. is supported in the form of a work contract funded bynational funds through FCT with reference DL57/2016/CP1364/CT0005, European Project: 337591,EC:FP7:ERC,ERC-2013-StG,EXTRA(2014), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE)-Swiss National Science Foundation (SNSF), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidade do Porto = University of Porto-Universidade do Porto = University of Porto, Université de Genève = University of Geneva (UNIGE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Faria, J. [0000-0002-6728-244X], Correia, A. C. M. [0000-0002-8946-8579], Leleu, A. [0000-0003-2051-7974], Lillo Box, J. [0000-0003-3742-1987], Santos, N. [0000-0003-4422-2919], Agencia Estatal de Investigación (AEI), FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao, Comisión Nacional de Investigación Científica y Tecnológica (CONICYT), European Research Council (ERC), ENGAGE SKA, PHOBOS, Portuguese Foundation for Science and Technology, Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Fundacao para a Ciencia e a Tecnologia (FCT), Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), and European Commission (EC)
Subjects: 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Context (language use), Astrophysics, polarimetric [Techniques], 01 natural sciences, Photometry (optics), planets and satellites: terrestrial planets, Planet, 0103 physical sciences, techniques: radial velocities, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), [PHYS]Physics [physics], radial velocities [Techniques], planets and satellites: composition, Astronomy and Astrophysics, Planetary system, Orbital period, interiors [Planets and satellites], Exoplanet, planets and satellites: interiors, planets and satellites: individual: LHS1140, Radial velocity, techniques: polarimetric, 13. Climate action, Space and Planetary Science, terrestrial planets [Planets and satellites], composition [Planets and satellites], individual: LHS1140 [Planets and satellites], [SDU.ASTR.GA]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Galactic Astrophysics [astro-ph.GA], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics
Abstract: Context. LHS 1140 is an M dwarf known to host two transiting planets at orbital periods of 3.77 and 24.7 days. They were detected with HARPS and Spitzer. The external planet (LHS 1140 b) is a rocky super-Earth that is located in the middle of the habitable zone of this low-mass star. All these properties place this system at the forefront of the habitable exoplanet exploration, and it therefore constitutes a relevant case for further astrobiological studies, including atmospheric observations. Aims. We further characterize this system by improving the physical and orbital properties of the known planets, search for additional planetary-mass components in the system, and explore the possibility of co-orbitals. Methods. We collected 113 new high-precision radial velocity observations with ESPRESSO over a 1.5-yr time span with an average photon-noise precision of 1.07 m s-1. We performed an extensive analysis of the HARPS and ESPRESSO datasets and also analyzed them together with the new TESS photometry. We analyzed the Bayesian evidence of several models with different numbers of planets and orbital configurations. Results. We significantly improve our knowledge of the properties of the known planets LHS 1140 b (Pb ∼ 24.7 days) and LHS 1140 c (Pc ∼ 3.77 days). We determine new masses with a precision of 6% for LHS 1140 b (6.48 ± 0.46 Mpdbl) and 9% for LHS 1140 c (mc = 1.78 ± 0.17 Mpdbl). This reduces the uncertainties relative to previously published values by half. Although both planets have Earth-like bulk compositions, the internal structure analysis suggests that LHS 1140 b might be iron-enriched and LHS 1140 c might be a true Earth twin. In both cases, the water content is compatible to a maximum fraction of 10-12% in mass, which is equivalent to a deep ocean layer of 779 ± 650 km for the habitable-zone planet LHS 1140 b. Our results also provide evidence for a new planet candidate in the system (md = 4.8 ± 1.1Mpdbl) on a 78.9-day orbital period, which is detected through three independent methods. The analysis also allows us to discard other planets above 0.5 Mpdbl for periods shorter than 10 days and above 2 Mpdbl for periods up to one year. Finally, our co-orbital analysis discards co-orbital planets in the tadpole and horseshoe configurations of LHS 1140 b down to 1 Mpdbl with a 95% confidence level (twice better than with the previous HARPS dataset). Indications for a possible co-orbital signal in LHS 1140 c are detected in both radial velocity (alternatively explained by a high eccentricity) and photometric data (alternatively explained by systematics), however. Conclusions. The new precise measurements of the planet properties of the two transiting planets in LHS 1140 as well as the detection of the planet candidate LHS 1140 d make this system a key target for atmospheric studies of rocky worlds at different stellar irradiations., With funding from the Spanish government through the "María de Maeztu Unit of Excellence" accreditation (MDM-2017-0737)
Published: 2020
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20. Discovery of a hot, transiting, Earth-sized planet and a second temperate, non-transiting planet around the M4 dwarf GJ 3473 (TOI-488)

Author: David R. Ciardi, Xavier Bonfils, Richard P. Schwarz, M. Lafarga, K. Kawauchi, P. Guerra, Sabine Reffert, E. Esparza-Borges, David W. Latham, Nuno C. Santos, H. Harakawa, Enric Palle, Stefan Dreizler, Víctor J. S. Béjar, Mayuko Mori, Noriharu Watanabe, S. Stock, Ansgar Reiners, Bernie Shiao, Joshua E. Schlieder, Sandra V. Jeffers, Diana Kossakowski, François Bouchy, A. Fukui, Motohide Tamura, A. Ueda, Masayuki Kuzuhara, Takayuki Kotani, Rachel A. Matson, Adrian Kaminski, D. D. Della-Rose, Steve B. Howell, Joshua N. Winn, Sara Seager, J. P. de Leon, Jose A. Caballero, Masahiro Ikoma, Roland Vanderspek, J. Kemmer, Norio Narita, Erica J. Gonzales, Ian Crossfield, N. Crouzet, John H. Livingston, Yuka Terada, Tianjun Gan, Philip S. Muirhead, T. Forveille, R. Cloutier, P. Schöfer, K. I. Collins, J. D. Twicken, Andreas Quirrenbach, Elisabeth Matthews, Néstor Espinoza, Martin Kürster, Mathias Zechmeister, Carlos Cifuentes, Karan Molaverdikhani, Rafael Luque, M. Omiya, Pedro J. Amado, X. Delfosse, P. T. Boyd, Jon M. Jenkins, Ana Glidden, P. Klagyivik, Taku Nishiumi, Teriyuki Hirano, Juan Carlos Morales, Martin Schlecker, P. Figueira, Jun Nishikawa, S. Vievard, Jose-Manuel Almenara, D. Galadí-Enríquez, Hannu Parviainen, George R. Ricker, Jessie L. Christiansen, T. Kurokawa, A. P. Hatzes, Klaus W. Hodapp, Karen A. Collins, Nicola Astudillo-Defru, P. Bluhm, Yasunori Hori, T. Kimura, Felipe Murgas, Ignasi Ribas, K. Isogai, Th. Henning, M. Cortés-Contreras, E. Herrero, N. Kusakabe, C. Rodríguez López, Z. Essack, German Research Foundation, Max Planck Society, European Commission, Consejo Superior de Investigaciones Científicas (España), Thuringian Ministry of Education, Science and Culture, Klaus Tschira Foundation, Ministerio de Economía y Competitividad (España), Junta de Andalucía, European Research Council, Ministerio de Ciencia, Innovación y Universidades (España), Comisión Nacional de Investigación Científica y Tecnológica (Chile), Science and Technology Facilities Council (UK), Generalitat de Catalunya, Japan Society for the Promotion of Science, Japan Science and Technology Agency, Fundação para a Ciência e a Tecnologia (Portugal), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Institut de Microélectronique, Electromagnétisme et Photonique - Laboratoire d'Hyperfréquences et Caractérisation (IMEP-LAHC), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), Université Grenoble Alpes (UGA), Instituto Nacional de Técnica Aeroespacial (INTA), Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)
Subjects: Extrasolare Planeten und Atmosphären, planets and satellites: detection, FOS: Physical sciences, individual: G 50-16 [Stars], Astrophysics, 01 natural sciences, techniques: photometric, Planet, 0103 physical sciences, techniques: radial velocities, 14. Life underwater, 010306 general physics, 010303 astronomy & astrophysics, planetary systems, Physics, Earth and Planetary Astrophysics (astro-ph.EP), stars: individual: G 50-16, radial velocities [Techniques], photometric [Techniques], stars: late-type, Astronomy and Astrophysics, Planetary systems, detection [Planets and satellites], 13. Climate action, Space and Planetary Science, late-type [Stars], Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Humanities, Astrophysics - Earth and Planetary Astrophysics
Abstract: Full list of authors: Kemmer, J.; Stock, S.; Kossakowski, D.; Kaminski, A.; Molaverdikhani, K.; Schlecker, M.; Caballero, J. A.; Amado, P. J.; Astudillo-Defru, N.; Bonfils, X.; Ciardi, D.; Collins, K. A.; Espinoza, N.; Fukui, A.; Hirano, T.; Jenkins, J. M.; Latham, D. W.; Matthews, E. C.; Narita, N.; Pallé, E.; Parviainen, H.; Quirrenbach, A.; Reiners, A.; Ribas, I.; Ricker, G.; Schlieder, J. E.; Seager, S.; Vanderspek, R.; Winn, J. N.; Almenara, J. M.; Béjar, V. J. S.; Bluhm, P.; Bouchy, F.; Boyd, P.; Christiansen, J. L.; Cifuentes, C.; Cloutier, R.; Collins, K. I.; Cortés-Contreras, M.; Crossfield, I. J. M.; Crouzet, N.; de Leon, J. P.; Della-Rose, D. D.; Delfosse, X.; Dreizler, S.; Esparza-Borges, E.; Essack, Z.; Forveille, Th.; Figueira, P.; Galadí-Enríquez, D.; Gan, T.; Glidden, A.; Gonzales, E. J.; Guerra, P.; Harakawa, H.; Hatzes, A. P.; Henning, Th.; Herrero, E.; Hodapp, K.; Hori, Y.; Howell, S. B.; Ikoma, M.; Isogai, K.; Jeffers, S. V.; Kürster, M.; Kawauchi, K.; Kimura, T.; Klagyivik, P.; Kotani, T.; Kurokawa, T.; Kusakabe, N.; Kuzuhara, M.; Lafarga, M.; Livingston, J. H.; Luque, R.; Matson, R.; Morales, J. C.; Mori, M.; Muirhead, P. S.; Murgas, F.; Nishikawa, J.; Nishiumi, T.; Omiya, M.; Reffert, S.; Rodríguez López, C.; Santos, N. C.; Schöfer, P.; Schwarz, R. P.; Shiao, B.; Tamura, M.; Terada, Y.; Twicken, J. D.; Ueda, A.; Vievard, S.; Watanabe, N.; Zechmeister, M., We present the confirmation and characterisation of GJ 3473 b (G 50-16, TOI-488.01), a hot Earth-sized planet orbiting an M4 dwarf star, whose transiting signal (P = 1.1980035 ± 0.0000018 d) was first detected by the Transiting Exoplanet Survey Satellite (TESS). Through a joint modelling of follow-up radial velocity observations with CARMENES, IRD, and HARPS together with extensive ground-based photometric follow-up observations with LCOGT, MuSCAT, and MuSCAT2, we determined a precise planetary mass, Mb = 1.86 ± 0.30 M·, and radius, Rb = 1.264 ± 0.050 R·. Additionally, we report the discovery of a second, temperate, non-transiting planet in the system, GJ 3473 c, which has a minimum mass, Mc sin i = 7.41 ± 0.91 M·, and orbital period, Pc = 15.509 ± 0.033 d. The inner planet of the system, GJ 3473 b, is one of the hottest transiting Earth-sized planets known thus far, accompanied by a dynamical mass measurement, which makes it a particularly attractive target for thermal emission spectroscopy. © 2020 ESO., CARMENES is an instrument at the Centro Astronomico Hispano-Aleman de Calar Alto (CAHA, Almeria, Spain). CARMENES was funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Cientificas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut fur Astronomie, Instituto de Astrofisica de Andalucia, Landessternwarte Konigstuhl, Institut de Ciencies de l'Espai, Insitut fur Astrophysik Gottingen, Universidad Complutense de Madrid, Thuringer Landessternwarte Tautenburg, Instituto de Astrofisica de Canarias, Hamburger Sternwarte, Centro de Astrobiologia and Centro Astronomico Hispano-Aleman), with additional contributions by the Spanish Ministry of Economy, the German Science Foundation through the Major Research Instrumentation Programme and Deutsche Forschungsgemeinschaft (DFG) Research Unit FOR2544 "Blue Planets around Red Stars", the Klaus Tschira Stiftung, the states of Baden-Wurttemberg and Niedersachsen, and by the Junta de Andalucia. Part of this work was funded by the Ministerio de Ciencia e Innovacion via projects PID2019-109522GB-C51/2/3/4 and AYA2016-79425C3-1/2/3-P, (MEXT/)JSPS KAKENHI via grants 15H02063, JP17H04574, 18H05442, JP18H01265, JP18H05439, 19J11805, JP19K14783, and 22000005, JST PRESTO via grant JPMJPR1775, FCT/MCTES through national funds (PIDDAC, PTDC/FIS-AST/32113/2017) via grant UID/FIS/04434/2019, FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao (POCI-010145-FEDER-032113), the FONDECYT project 3180063, Fundacao para a Ciencia e a Tecnologia through national funds and by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalizacao by these grants: UID/FIS/04434/2019; UIDB/04434/2020; UIDP/04434/2020; PTDC/FIS-AST/32113/2017 & POCI-01-0145-FEDER-032113; PTDC/FISAST/28953/2017 & POCI-01-0145-FEDER-028953. and the International Graduate Program for Excellence in Earth-Space Science. Part of the data analysis was carried out on the Multi-wavelength Data Analysis System operated by the Astronomy Data Center, National Astronomical Observatory of Japan. Funding for the TESS mission is provided by NASA's Science Mission directorate. We acknowledge the use of public TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. Resources supporting this work were provided by the NASA High-End Computing Program through the NASA Advanced Supercomputing Division at Ames Research Center for the production of the SPOC data products. This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes. This work makes use of observations from the LCOGT network. The analysis of this work has made use of a wide variety of public available software packages that are not referenced in the manuscript: Exo-Striker (Trifonov 2019), astropy (Astropy Collaboration 2018), scipy (Virtanen et al. 2020), numpy (Oliphant 2006), matplotlib (Hunter 2007), tqdm (da Costa-Luis 2019), pandas (The pandas development team 2020), seaborn (Waskom et al. 2020), lightkurve (Lightkurve Collaboration 2018) and PyFITS (Barrett et al. 2012).
Published: 2020
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21. A pair of TESS planets spanning the radius valley around the nearby mid-M dwarf LTT 3780

Author: Andrew W. Mann, Dimitar Sasselov, Jon M. Jenkins, Charles A. Beichman, Steve B. Howell, F. Lienhard, David Charbonneau, Joseph E. Rodriguez, Giampaolo Piotto, Ken Rice, Avet Harutyunyan, Matteo Pinamonti, Eric D. Lopez, Laura Kreidberg, David W. Latham, Xavier Dumusque, Mercedes Lopez-Morales, Michel Mayor, George R. Ricker, Nicola Astudillo-Defru, Jack J. Lissauer, Douglas A. Caldwell, Kevin I. Collins, A. Magazzu, Joseph D. Twicken, Joshua E. Schlieder, Andrew Collier Cameron, David F. Phillips, Xavier Delfosse, Joshua N. Winn, Dennis M. Conti, M. Stalport, Rosario Cosentino, Sara Seager, Rodrigo F. Díaz, Annelies Mortier, Sébastien Lépine, Patricia T. Boyd, Rachel A. Matson, John F. Kielkopf, David R. Ciardi, Stéphane Udry, Cesar Briceno, Thierry Forveille, Nicholas M. Law, Samuel N. Quinn, Adriano Ghedina, Lars A. Buchhave, Ennio Poretti, Nuno C. Santos, Karen A. Collins, René Doyon, Xavier Bonfils, Emilio Molinari, Aldo F. M. Fiorenzano, Jason D. Eastman, Eric L. N. Jensen, Étienne Artigau, Alessandro Sozzetti, Jonathan Irwin, Michael Vezie, Benjamin V. Rackham, Pedro Figueira, Mario Damasso, L. Mignon, Damien Ségransan, Francesco Pepe, Claudio Melo, Carl Ziegler, Jennifer G. Winters, Elisabeth Matthews, José Renan de Medeiros, Luca Di Fabrizio, Giuseppina Micela, Christophe Lovis, Ian J. M. Crossfield, François Bouchy, Christopher J. Burke, J. M. Almenara, Roland Vanderspek, John Asher Johnson, Ryan Cloutier, Peter Tenenbaum, Christopher A. Watson, Courtney D. Dressing, Robert Massey, Erica J. Gonzales, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Universidad Católica de la Santísima Concepción (UCSC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Cloutier, R [0000-0001-5383-9393], Eastman, JD [0000-0003-3773-5142], Rodriguez, JE [0000-0001-8812-0565], Mortier, A [0000-0001-7254-4363], Pinamonti, M [0000-0002-4445-1845], Lienhard, F [0000-0003-4047-0771], Latham, DW [0000-0001-9911-7388], Collins, KA [0000-0001-6588-9574], Massey, R [0000-0001-8879-7138], Winters, JG [0000-0001-6031-9513], Charbonneau, D [0000-0002-9003-484X], Ziegler, C [0000-0002-0619-7639], Matthews, E [0000-0003-0593-1560], Kreidberg, L [0000-0003-0514-1147], Quinn, SN [0000-0002-8964-8377], Ricker, G [0000-0003-2058-6662], Vanderspek, R [0000-0001-6763-6562], Seager, S [0000-0002-6892-6948], Winn, J [0000-0002-4265-047X], Jenkins, JM [0000-0002-4715-9460], Udry, S [0000-0001-7576-6236], Twicken, JD [0000-0002-6778-7552], Tenenbaum, P [0000-0002-1949-4720], Sozzetti, A [0000-0002-7504-365X], Ségransan, D [0000-0003-2355-8034], Schlieder, JE [0000-0001-5347-7062], Sasselov, D [0000-0001-7014-1771], Santos, NC [0000-0003-4422-2919], Rackham, BV [0000-0002-3627-1676], Poretti, E [0000-0003-1200-0473], Piotto, G [0000-0002-9937-6387], Molinari, E [0000-0002-1742-7735], Micela, G [0000-0002-9900-4751], De Medeiros, JR [0000-0001-8218-1586], Matson, RA [0000-0001-7233-7508], Mann, AW [0000-0003-3654-1602], Magazzú, A [0000-0003-1259-4371], López-Morales, M [0000-0003-3204-8183], Lissauer, JJ [0000-0001-6513-1659], Law, N [0000-0001-9380-6457], Kielkopf, JF [0000-0003-0497-2651], Jensen, ELN [0000-0002-4625-7333], Howell, SB [0000-0002-2532-2853], Ghedina, A [0000-0003-4702-5152], Forveille, T [0000-0003-0536-4607], Figueira, P [0000-0001-8504-283X], Dumusque, X [0000-0002-9332-2011], Dressing, CD [0000-0001-8189-0233], Díaz, RF [0000-0001-9289-5160], Conti, DM [0000-0003-2239-0567], Collins, KI [0000-0003-2781-3207], Ciardi, D [0000-0002-5741-3047], Caldwell, DA [0000-0003-1963-9616], Burke, C [0000-0002-7754-9486], Buchhave, L [0000-0003-1605-5666], Boyd, P [0000-0003-0442-4284], and Apollo - University of Cambridge Repository
Subjects: Radial velocity, 010504 meteorology & atmospheric sciences, Stellar mass, NDAS, FOS: Physical sciences, Astrophysics, M dwarf stars, 01 natural sciences, Planet, 0103 physical sciences, QB Astronomy, Spectroscopy, 010303 astronomy & astrophysics, Exoplanet systems, QC, 0105 earth and related environmental sciences, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astronomy and Astrophysics, Radius, Planetary system, Photoevaporation, Stars, QC Physics, Space and Planetary Science, astro-ph.EP, Transit photometry, Low Mass, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the confirmation of two new planets transiting the nearby mid-M dwarf LTT 3780 (TIC 36724087, TOI-732, $V=13.07$, $K_s=8.204$, $R_s$=0.374 R$_{\odot}$, $M_s$=0.401 M$_{\odot}$, d=22 pc). The two planet candidates are identified in a single TESS sector and are validated with reconnaissance spectroscopy, ground-based photometric follow-up, and high-resolution imaging. With measured orbital periods of $P_b=0.77$ days, $P_c=12.25$ days and sizes $r_{p,b}=1.33\pm 0.07$ R$_{\oplus}$, $r_{p,c}=2.30\pm 0.16$ R$_{\oplus}$, the two planets span the radius valley in period-radius space around low mass stars thus making the system a laboratory to test competing theories of the emergence of the radius valley in that stellar mass regime. By combining 63 precise radial-velocity measurements from HARPS and HARPS-N, we measure planet masses of $m_{p,b}=2.62^{+0.48}_{-0.46}$ M$_{\oplus}$ and $m_{p,c}=8.6^{+1.6}_{-1.3}$ M$_{\oplus}$, which indicates that LTT 3780b has a bulk composition consistent with being Earth-like, while LTT 3780c likely hosts an extended H/He envelope. We show that the recovered planetary masses are consistent with predictions from both photoevaporation and from core-powered mass loss models. The brightness and small size of LTT 3780, along with the measured planetary parameters, render LTT 3780b and c as accessible targets for atmospheric characterization of planets within the same planetary system and spanning the radius valley., Comment: Accepted to AJ. 8 figures, 6 tables. CSV file of the RV measurements (i.e. Table 2) are included in the source code
Published: 2020
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22. A hot terrestrial planet orbiting the bright M dwarf L 168-9 unveiled by TESS

Author: Sharon X. Wang, Diana Dragomir, Étienne Artigau, Pedro Figueira, Z. Essack, Andrés Jordán, David R. Anderson, Stéphane Udry, Nicholas M. Law, Thomas Henning, Roland Vanderspek, Rhodes Hart, Howard M. Relles, T. Forveille, C. Ziegler, C. Lovis, J. Villasenor, Pascal Torres, Jon M. Jenkins, Johanna Teske, Rodrigo F. Díaz, Joshua N. Winn, J. R. De Medeiros, David Charbonneau, Ryan Cloutier, Ian J. M. Crossfield, Jose-Manuel Almenara, Fabo Feng, Daniel A. Nusdeo, Keivan G. Stassun, S. Shectman, Nuno C. Santos, Dennis M. Conti, Damien Ségransan, Jennifer G. Winters, Ana Glidden, James S. Jenkins, N. Guerrero, François Bouchy, Misty Davies, Sara Seager, Andrew W. Mann, C. Melo, Avi Shporer, Tianjun Gan, Coel Hellier, Giovanni Isopi, Néstor Espinoza, René Doyon, Elliott P. Horch, Rafael Brahm, Jason D. Eastman, Xavier Bonfils, Jeffrey C. Smith, Francesco Pepe, David W. Latham, John F. Kielkopf, Karen A. Collins, Nicola Astudillo-Defru, R. P. Butler, Cesar Briceno, X. Delfosse, Felipe Murgas, Mark E. Rose, George Zhou, Ronald E. Mennickent, L. Mignon, George R. Ricker, F. Mallia, Jeffrey D. Crane, Departamento de Matemática y Fı́sica Aplicadas [Concepcion] (DMFA), Universidad Católica de la Santísima Concepción (UCSC), Université du Québec à Rimouski (UQAR), Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)
Subjects: 010504 meteorology & atmospheric sciences, Library science, FOS: Physical sciences, RADIAL VELOCITIES [TECHNIQUES], Astrophysics, Q1, LATE-TYPE [STARS], 01 natural sciences, purl.org/becyt/ford/1 [https], 0103 physical sciences, PLANETARY SYSTEMS, INDIVIDUAL: L 168-9 [STARS], 010303 astronomy & astrophysics, QB600, QC, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), European research, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], PHOTOMETRIC [TECHNIQUES], Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Christian ministry, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics, QB799
Abstract: We report the detection of a transiting super-Earth-sized planet (R=1.39+-0.09 Rearth) in a 1.4-day orbit around L 168-9 (TOI-134),a bright M1V dwarf (V=11, K=7.1) located at 25.15+-0.02 pc. The host star was observed in the first sector of the Transiting Exoplanet Survey Satellite (TESS) mission and, for confirmation and planet mass measurement, was followed up with ground-based photometry, seeing-limited and high-resolution imaging, and precise radial velocity (PRV) observations using the HARPS and PFS spectrographs. Combining the TESS data and PRV observations, we find the mass of L168-9 b to be 4.60+-0.56 Mearth, and thus the bulk density to be 1.74+0.44-0.33 times larger than that of the Earth. The orbital eccentricity is smaller than 0.21 (95% confidence). This planet is a Level One Candidate for the TESS Mission's scientific objective - to measure the masses of 50 small planets - and is one of the most observationally accessible terrestrial planets for future atmospheric characterization., Comment: 14 pages, 8 figures, 3 tables. Accepted for publication in astronomy and Astrophysics
Published: 2020
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23. LHS 1815b: The first thick-disk planet detected by TESS

Author: Teruyuki Hirano, Jennifer G. Winters, Jonathan Irwin, Gabor Furesz, Elisa Quintana, Karen A. Collins, Roland Vanderspek, Shude Mao, George R. Ricker, John H. Livingston, Eric L. N. Jensen, Sara Seager, Carl Ziegler, Steve B. Howell, Andrew W. Mann, Peter Tenenbaum, Nicholas M. Law, Natalia Guerrero, Douglas A. Caldwell, Joshua N. Winn, Xavier Bonfils, Bárbara Rojas-Ayala, Joseph D. Twicken, Guillem Anglada-Escudé, David R. Anderson, David W. Latham, Jon M. Jenkins, Cesar Briceno, Pamela Rowden, Avi Shporer, Nicola Astudillo-Defru, Tianjun Gan, Keivan G. Stassun, Rafael Luque, Coel Hellier, Davide Gandolfi, Alessandro A. Trani, Chelsea X. Huang, National Aeronautics and Space Administration (US), University of Leeds, Universidad de Córdoba [Cordoba], Vanderbilt University [Nashville], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)
Subjects: Stellar kinematics, Radial velocity, 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Planet, 0103 physical sciences, Thick disk, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astrometric exoplanet detection, Astrometry, Transit photometry, Astronomy and Astrophysics, Radius, Planetary system, Galactic plane, Astrophysics - Astrophysics of Galaxies, Stars, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: TESS: et al., arXiv:2003.04525v1, We report the first discovery of a thick-disk planet, LHS 1815b (TOI-704b, TIC 260004324), detected in the Transiting Exoplanet Survey Satellite (TESS) survey. LHS 1815b transits a bright (V = 12.19 mag, K = 7.99 mag) and quiet M dwarf located 29.87 ± 0.02 pc away with a mass of 0.502 ± 0.015 M⊙ and a radius of 0.501 ± 0.030 R⊙. We validate the planet by combining space- and ground-based photometry, spectroscopy, and imaging. The planet has a radius of 1.088 ± 0.064 R⊕ with a 3σ mass upper limit of 8.7 M⊕. We analyze the galactic kinematics and orbit of the host star LHS 1815 and find that it has a large probability (Pthick/Pthin = 6482) to be in the thick disk with a much higher expected maximal height (Zmax = 1.8 kpc) above the Galactic plane compared with other TESS planet host stars. Future studies of the interior structure and atmospheric properties of planets in such systems using, for example, the upcoming James Webb Space Telescope, can investigate the differences in formation efficiency and evolution for planetary systems between different Galactic components (thick disks, thin disks, and halo)., Funding for the TESS mission is provided by NASA’s Science Mission directorate. This work is partly supported by the National Science Foundation of China (grant No. 11390372 and 11761131004 to S.M. and G.T.J.). We acknowledge the use of TESS Alert data from pipelines at the TESS Science Office and at the TESS Science Processing Operations Center. Resources supporting this work were provided by the NASA High-End Computing (HEC) Program through the NASA Advanced Supercomputing (NAS) Division at Ames Research Center for the production of the SPOC data products. J.G.W. is supported by a grant from the John Templeton Foundation. The opinions expressed in this publication are those of the authors and do not necessarily reflect the views of the John Templeton Foundation. A.A.T. acknowledges support from JSPS KAKENHI Grant Number 17F17764 and 17H06360. C.Z. is supported by a Dunlap Fellowship at the Dunlap Institute for Astronomy & Astrophysics, funded through an endowment established by the Dunlap family and the University of Toronto. Some of the observations in the paper made use of the High-Resolution Imaging instrument Zorro at Gemini-South). Zorro was funded by the NASA Exoplanet Exploration Program and built at the NASA Ames Research Center by Steve B. Howell, Nic Scott, Elliott P. Horch, and Emmett Quigley. This research has made use of the Exoplanet Follow-up Observation Program website, which is operated by the California Institute of Technology, under contract with the National Aeronautics and Space Administration under the Exoplanet Exploration Program. This paper includes data collected by the TESS mission, which are publicly available from the Mikulski Archive for Space Telescopes (MAST). This research made use of observations from the LCO network, WASP-South and ESO: 3.6m (HARPS). N. A.-D. acknowledges the support of FONDECYT project 3180063. B.R-A acknowledges the funding support from FONDECYT through grant 11181295.
Published: 2020
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24. Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS). V. Detection of sodium on the bloated super-Neptune WASP-166b

Author: Vincent Bourrier, David Ehrenreich, Stéphane Udry, E. Linder, Damien Ségransan, Monika Lendl, Aurélien Wyttenbach, O. Attia, Heather M. Cegla, Baptiste Lavie, Francesco Pepe, C. H. F. Melo, H. J. Hoeijmakers, C. Lovis, Kevin Heng, Julia V. Seidel, Daniel Bayliss, Nicola Astudillo-Defru, L. A. dos Santos, and Romain Allart
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Radial velocity, Space and Planetary Science, Neptune, Planet, 0103 physical sciences, Transit (astronomy), Hot Neptune, 010303 astronomy & astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Planet formation processes or evolution mechanisms are surmised to be at the origin of the hot Neptune desert. Studying exoplanets currently living within or at the edge of this desert could allow disentangling the respective roles of formation and evolution. We present the HARPS transmission spectrum of the bloated super-Neptune WASP-166b, located at the outer rim of the Neptune desert. Neutral sodium is detected at the 3.4 $\sigma$ level ($0.455 \pm 0.135 \%$), with a tentative indication of line broadening, which could be caused by winds blowing sodium farther into space, a possible manifestation of the bloated character of these highly irradiated worlds. We put this detection into context with previous work claiming a non-detection of sodium in the same observations and show that the high noise in the trace of the discarded stellar sodium lines was responsible for the non-detection. We highlight the impact of this low signal-to-noise remnant on detections for exoplanets similar to WASP-166b., Comment: 7 pages, 7 figures, accepted for publication in A&A
Published: 2020
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25. The high-energy environment and atmospheric escape of the mini-Neptune K2-18 b

Author: David Ehrenreich, Nicola Astudillo-Defru, Stéphane Udry, Xavier Bonfils, Vincent Bourrier, Christophe Lovis, Leonardo A. dos Santos, Francesco Pepe, François Forget, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Universidad Católica de la Santísima Concepción (UCSC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Université de Genève = University of Geneva (UNIGE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
Subjects: stars, stars: chromospheres, 010504 meteorology & atmospheric sciences, kinematics and dynamics, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 7. Clean energy, 01 natural sciences, Atmosphere, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, K2-18 -stars, Transit (astronomy), individual, 010303 astronomy & astrophysics, Space Telescope Imaging Spectrograph, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), ISM: kinematics and dynamics, planets and satellites: atmospheres, [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph], Atmospheric escape, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], atmospheres -ISM, Astronomy and Astrophysics, stars: individual: K2-18, Redshift, Radiation pressure, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, chromospheres -planets and satellites, Mini-Neptune, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: K2-18 b is a transiting mini-Neptune that orbits a nearby (38 pc) cool M3 dwarf and is located inside its region of temperate irradiation. We report on the search for hydrogen escape from the atmosphere K2-18 b using Lyman-$\alpha$ transit spectroscopy with the Space Telescope Imaging Spectrograph (STIS) instrument installed on the Hubble Space Telescope (HST). We analyzed the time-series of the fluxes of the stellar Lyman-$\alpha$ emission of K2-18 in both its blue- and redshifted wings. We found that the average blueshifted emission of K2-18 decreases by $67\% \pm 18\%$ during the transit of the planet compared to the pre-transit emission, tentatively indicating the presence of H atoms escaping vigorously and being blown away by radiation pressure. This interpretation is not definitive because it relies on one partial transit. Based on the reconstructed Lyman-$\alpha$ emission of K2-18, we estimate an EUV irradiation between $10^1-10^2$ erg s$^{-1}$ cm$^{-2}$ and a total escape rate in the order of $10^8$ g s$^{-1}$. The inferred escape rate suggests that the planet will lose only a small fraction (< 1%) of its mass and retain its volatile-rich atmosphere during its lifetime. More observations are needed to rule out stellar variability effects, confirm the in-transit absorption and better assess the atmospheric escape and high-energy environment of K2-18 b., Comment: 5 pages, 4 figures, accepted for publication in A&A Letters, V2 with editorial corrections
Published: 2020
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26. Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS). III. Atmospheric structure of the misaligned ultra-hot Jupiter WASP-121b

Author: C. Melo, Francesco Pepe, A. Suarez-Mascareno, Nicola Astudillo-Defru, M. Cretignier, Damien Ségransan, T. Kuntzer, Valerio Nascimbeni, Monika Lendl, Aurélien Wyttenbach, C. Lovis, Kevin Heng, Heather M. Cegla, H. Giles, Stéphane Udry, Romain Allart, Lorenzo Pino, H. J. Hoeijmakers, Felipe Murgas, Xavier Dumusque, Baptiste Lavie, David Ehrenreich, Daniel Kitzmann, and Vincent Bourrier
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Tidal locking, Jupiter, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Hot Jupiter, Differential rotation, Transit (astronomy), Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract: Ultra-hot Jupiters offer interesting prospects for expanding our theories on dynamical evolution and the properties of extremely irradiated atmospheres. In this context, we present the analysis of new optical spectroscopy for the transiting ultra-hot Jupiter WASP-121b. We first refine the orbital properties of WASP-121b, which is on a nearly polar (obliquity $\psi^{\rm North}$=88.1$\pm$0.25$^{\circ}$ or $\psi^{\rm South}$=91.11$\pm$0.20$^{\circ}$) orbit, and exclude a high differential rotation for its fast-rotating (P$, Comment: 20 pages, 15 figures, accepted for publication in A&A on 19 December 2019
Published: 2020

27. Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS). IV. A spectral inventory of atoms and molecules in the high-resolution transmission spectrum of WASP-121 b

Author: Damien Ségransan, Daniel Kitzmann, Julia V. Seidel, Valerio Nascimbeni, Monika Lendl, Aurélien Wyttenbach, Daniel Bayliss, Sergei N. Yurchenko, Heather M. Cegla, David Ehrenreich, Lorenzo Pino, Andrea Gebek, Kevin Heng, C. H. F. Melo, C. Lovis, Baptiste Lavie, Romain Allart, H. J. Hoeijmakers, Apurva Oza, Jan Philip Sindel, Vincent Bourrier, Francesco Pepe, Felipe Murgas, Nicola Astudillo-Defru, and Stéphane Udry
Subjects: gaseous planets [planets and satellites], 010504 meteorology & atmospheric sciences, EXTRASOLAR PLANET, FOS: Physical sciences, Context (language use), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astronomy & Astrophysics, MASS, 01 natural sciences, Computer Science::Digital Libraries, Spectral line, Jupiter, 0103 physical sciences, Hot Jupiter, ABSORPTION, Spectral resolution, Spectroscopy, SOLAR, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Science & Technology, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, atmospheres [planets and satellites], Exoplanet, Physics::History of Physics, 3. Good health, LINE LISTS, Chemical species, INFRARED LASER SPECTROSCOPY, TIS, Space and Planetary Science, TITANIUM, GIANT PLANET, Physical Sciences, HD 189733B, spectroscopic [techniques], Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: Aims: We survey the transmission spectrum of WASP-121 b for line-absorption by metals and molecules at high spectral resolution, and elaborate on existing interpretations of the optical transmission spectrum observed with HST/STIS and WFC3. Methods: We use the cross-correlation technique and direct differential spectroscopy to search for sodium and other neutral and ionised atoms, TiO, VO and SH in high-resolution transit spectra obtained with the HARPS spectrograph. We inject models assuming chemical and hydrostatic equilibrium with varying temperature and composition to enable model comparison, and employ two bootstrap methods to test the robustness of our detections. Results: We detect neutral Mg, Na, Ca, Cr, Fe, Ni and V, which we predict exists in equilibrium with a significant quantity of VO, supporting earlier observations by HST/WFC3. Non-detections of Ti and TiO support the hypothesis that Ti is depleted via a cold-trap mechanism as has been proposed in the literature. Atomic line depths are under-predicted by hydrostatic models by a factor of 1.5 to 8, confirming recent findings that the atmosphere is extended. We predict the existence of significant concentrations of gas-phase TiO$_2$, VO$_2$ and TiS, which could be important absorbers at optical and NIR wavelengths in hot Jupiter atmospheres, but for which accurate line-list data is currently not available. We find no evidence for absorption by SH, and find that inflated atomic lines can plausibly explain the slope of the transmission spectrum observed in the NUV with HST/STIS. The Na D lines are significantly broadened and show a difference in their respective depths of 15 scale heights, which is not expected from isothermal hydrostatic theory., Comment: Accepted for publication in A&A - June 19, 2020
Published: 2020

28. New Galactic β Lyrae-type Binaries Showing Superorbital Photometric Cycles

Author: Gonzalo Rojas García, Igor Soszyński, Patrik Iwanek, Nicola Astudillo-Defru, Paula Gorrini, Ronald E. Mennickent, and Juan Garcés
Subjects: Physics, Beta Lyrae, Milky Way, Astronomy and Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Type (model theory), Astrophysics - Astrophysics of Galaxies, Gravitational lens, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Bulge, Binary star, Astrophysics::Solar and Stellar Astrophysics, Variable star, Astrophysics::Galaxy Astrophysics, dPVS
Abstract: We present the discovery of 32 new double periodic variables (DPVs) located toward the Galactic bulge. We found these objects among the nearly half a million binary stars published by the Optical Gravitational Lensing Experiment project. With this discovery, we increase the number of known DPVs in the Milky Way by a factor of 2. The new set of DPVs contains 31 eclipsing binaries and one ellipsoidal variable star. The orbital periods cover the range from 1.6 to 26 days, while long periods are detected between 47 and 1144 days. Our analysis confirms a known correlation between orbital and long periods that is also observed in similar systems in the Magellanic Clouds., Comment: 8 pages, 7 figures
Published: 2021
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29. The SOPHIE search for northern extrasolar planets. XVI. HD 158259: A compact planetary system in a near-3:2 mean motion resonance chain

Author: Nuno C. Santos, Damien Ségransan, J.-B. Delisle, Xavier Dumusque, Xavier Bonfils, Gregory W. Henry, Flavien Kiefer, Francesco Pepe, Isabelle Boisse, Luc Arnold, B. Courcol, C. Moutou, Rodrigo F. Díaz, François Bouchy, Nathan Hara, M. Stalport, Olivier Demangeon, Simon Borgniet, T. Lopez, J. Rey, M. J. Hobson, B. Brugger, L. Mignon, S. Dalal, T. Forveille, Vincent Bourrier, Magali Deleuil, O. Mousis, P. A. Wilson, J. Rodrigues, X. Delfosse, Nicola Astudillo-Defru, Alexandre Santerne, Guillaume Hébrard, and Stéphane Udry
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Stellar rotation, FOS: Physical sciences, Astronomy and Astrophysics, Radius, Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Radial velocity, Mean motion, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, Planet, 0103 physical sciences, Magnitude (astronomy), Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Since 2011, the SOPHIE spectrograph has been used to search for Neptunes and super-Earths in the Northern Hemisphere. As part of this observational program, 290 radial velocity measurements of the 6.4 V magnitude star HD 158259 were obtained. Additionally, TESS photometric measurements of this target are available. We present an analysis of the SOPHIE data and compare our results with the output of the TESS pipeline. The radial velocity data, ancillary spectroscopic indices, and ground-based photometric measurements were analyzed with classical and $\ell_1$ periodograms. The stellar activity was modeled as a correlated Gaussian noise and its impact on the planet detection was measured with a new technique. The SOPHIE data support the detection of five planets, each with $m \sin i \approx 6 M_\oplus$, orbiting HD 158259 in 3.4, 5.2, 7.9, 12, and 17.4 days. Though a planetary origin is strongly favored, the 17.4 d signal is classified as a planet candidate due to a slightly lower statistical significance and to its proximity to the expected stellar rotation period. The data also present low frequency variations, most likely originating from a magnetic cycle and instrument systematics. Furthermore, the TESS pipeline reports a significant signal at 2.17 days corresponding to a planet of radius $\approx 1.2 R_\oplus$. A compatible signal is seen in the radial velocities, which confirms the detection of an additional planet and yields a $\approx 2 M_\oplus$ mass estimate. We find a system of five planets and a strong candidate near a 3:2 mean motion resonance chain orbiting HD 158259. The planets are found to be outside of the two and three body resonances., Accepted for publication in Astronomy & Astrophysics
Published: 2019

30. Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS). II. A broadened sodium feature on the ultra-hot giant WASP-76b

Author: C. Melo, Monika Lendl, Aurélien Wyttenbach, Heather M. Cegla, Lorenzo Pino, Julia V. Seidel, R. Joseph, Romain Allart, David Barrado, C. Lovis, Damien Ségransan, Kevin Heng, Daniel Bayliss, Vincent Bourrier, Nicola Astudillo-Defru, David Ehrenreich, Baptiste Lavie, A. Deline, Chloe Fisher, Stéphane Udry, Francesco Pepe, and Low Energy Astrophysics (API, FNWI)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Gas giant, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Atmosphere, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Transit (astronomy), Astrophysics::Earth and Planetary Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: High-resolution optical spectroscopy is a powerful tool to characterise exoplanetary atmospheres from the ground. The sodium D lines, with their large cross sections, are especially suited to study the upper layers of atmospheres in this context. We report on the results from HEARTS, a spectroscopic survey of exoplanet atmospheres, performing a comparative study of hot gas giants to determine the effects of stellar irradiation. In this second installation of the series, we highlight the detection of neutral sodium on the ultra-hot giant WASP-76b. We observed three transits of the planet using the HARPS high-resolution spectrograph at the ESO 3.6m telescope and collected 175 spectra of WASP-76. We repeatedly detect the absorption signature of neutral sodium in the planet atmosphere ($0.371\pm0.034\%$; $10.75 \sigma$ in a $0.75$ \r{A} passband). The sodium lines have a Gaussian profile with full width at half maximum (FWHM) of $27.6\pm2.8$ km s$^{-1}$. This is significantly broader than the line spread function of HARPS ($2.7$ km s$^{-1}$). We surmise that the observed broadening could trace the super-rotation in the upper atmosphere of this ultra-hot gas giant., Comment: 11 pages, 9 figures; accepted by Astronomy and Astrophysics (29.01.2019)
Published: 2019

31. The SOPHIE search for northern extrasolar planets XV. A Warm Neptune around the M-dwarf Gl378

Author: N. Cabrera Salazar, T. Forveille, S. Dalal, X. Delfosse, Flavien Kiefer, Rodrigo F. Díaz, C. Moutou, Stéphane Udry, Vincent Bourrier, Isabelle Boisse, Magali Deleuil, O. Mousis, Nicola Astudillo-Defru, Nuno C. Santos, M. J. Hobson, A. Santerne, Damien Ségransan, B. Courcol, L. Mignon, Xavier Dumusque, Xavier Bonfils, M. Stalport, Nathan Hara, S. Borgniet, P. A. Wilson, Luc Arnold, B. Brugger, Francesco Pepe, G. Hebrard, J. Rey, François Bouchy, Olivier Demangeon, T. Lopez, and G. Montagnier
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), Minimum mass, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Orbital period, 01 natural sciences, Exoplanet, 010309 optics, Radial velocity, Space and Planetary Science, Neptune, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Hot Neptune, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the detection of a Warm Neptune orbiting the M-dwarf Gl378, using radial velocity measurements obtained with the SOPHIE spectrograph at the Observatoire de Haute-Provence. The star was observed in the context of the SOPHIE exoplanets consortium's subprogramme dedicated to finding planets around M-dwarfs. Gl378 is an M1 star, of solar metallicity, at a distance of 14.96 pc. The single planet detected, Gl378 b, has a minimum mass of 13.02 $\rm M_{Earth}$ and an orbital period of 3.82 days, which place it at the lower boundary of the Hot Neptune desert. As one of only a few such planets around M-dwarfs, Gl378 b provides important clues to the evolutionary history of these close-in planets. In particular, the eccentricity of 0.1 may point to a high-eccentricity migration. The planet may also have lost part of its envelope due to irradiation., 10 pages, 8 figures, accepted for publication in A&A
Published: 2019

32. The SOPHIE search for northern extrasolar planets. XIV. A temperate ($T_\mathrm{eq}\sim 300$ K) super-earth around the nearby star Gliese 411

Author: Nuno C. Santos, Damien Ségransan, Luc Arnold, Isabelle Boisse, Magali Deleuil, O. Mousis, Francesco Pepe, Rodrigo F. Díaz, S. Perruchot, Stéphane Udry, Gregory W. Henry, B. Brugger, M. J. Hobson, F. Dolon, L. Mignon, Xavier Bonfils, Nathan Hara, T. Forveille, François Bouchy, Xavier Dumusque, Y. Richaud, Flavien Kiefer, C. Moutou, S. Dalal, Guillaume Hébrard, Paul Wilson, Alexandre Santerne, N. Unger, T. Lopez, Nicola Astudillo-Defru, Vincent Bourrier, M. Stalport, X. Delfosse, R. Sottile, François Moreau, and Olivier Demangeon
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), Super-Earth, 010308 nuclear & particles physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Atmosphere, Radial velocity, Amplitude, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, 010303 astronomy & astrophysics, Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics
Abstract: Periodic radial velocity variations in the nearby M-dwarf star Gl411 are reported, based on measurements with the SOPHIE spectrograph. Current data do not allow us to distinguish between a 12.95-day period and its one-day alias at 1.08 days, but favour the former slightly. The velocity variation has an amplitude of 1.6 m/s, making this the lowest-amplitude signal detected with SOPHIE up to now. We have performed a detailed analysis of the significance of the signal and its origin, including extensive simulations with both uncorrelated and correlated noise, representing the signal induced by stellar activity. The signal is significantly detected, and the results from all tests point to its planetary origin. Additionally, the presence of an additional acceleration in the velocity time series is suggested by the current data. On the other hand, a previously reported signal with a period of 9.9 days, detected in HIRES velocities of this star, is not recovered in the SOPHIE data. An independent analysis of the HIRES dataset also fails to unveil the 9.9-day signal. If the 12.95-day period is the real one, the amplitude of the signal detected with SOPHIE implies the presence of a planet, called Gl411 b, with a minimum mass of around three Earth masses, orbiting its star at a distance of 0.079 AU. The planet receives about 3.5 times the insolation received by Earth, which implies an equilibrium temperature between 255 K and 350 K, and makes it too hot to be in the habitable zone. At a distance of only 2.5 pc, Gl411 b, is the third closest low-mass planet detected to date. Its proximity to Earth will permit probing its atmosphere with a combination of high-contrast imaging and high-dispersion spectroscopy in the next decade., Comment: Accepted for publication in Astronomy & Astrophysics. 17 pages, 15 figures (plus Appendices). Added new co-author; minor changes in text
Published: 2019
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33. On the long cycle variability of the Algol OGLE-LMC-DPV-065 and its stellar, orbital and disk parameters

Author: L. Celedón, Nicola Astudillo-Defru, Igor Soszyński, Ashish Raj, Claus Tappert, José G. Fernández-Trincado, Th. Rivinius, Linda Schmidtobreick, Petr Hadrava, G. Djurašević, Neustroev, Radosław Poleski, Ronald E. Mennickent, M. Cabezas, I. Porritt, European Southern Observatory [Santiago] (ESO), European Southern Observatory (ESO), Ohio State University [Columbus] (OSU), Astronomical Observatory [Warsaw], Faculty of Physics [Warsaw] (FUW), University of Warsaw (UW)-University of Warsaw (UW), Universidad de Concepción [Chile], Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Instituto de Astronomia y ciencias Planetarias de Atacama (INCT), and Universidad de Atacama
Subjects: FOS: Physical sciences, Astrophysics, 01 natural sciences, 0103 physical sciences, Thick disk, Circular orbit, close, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Solar and Stellar Astrophysics (astro-ph.SR), Physics, 010308 nuclear & particles physics, Astronomy and Astrophysics, Radius, activity [spectroscopic - stars], Mass ratio, Orbital period, Light curve, Orbit, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, binaries: eclipsing [stars], circumstellar matter - fundamental parameters, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract: OGLE-LMC-DPV-065 is an interacting binary whose double-hump long photometric cycle remains hitherto unexplained. We analyze photometric time series available in archive datasets spanning 124 years and present the analysis of new high-resolution spectra. A refined orbital period is found of 10\fd0316267 $\pm$ 0\fd0000056 without any evidence of variability. In spite of this constancy, small but significant changes in timings of the secondary eclipse are detected. We show that the long period continuously decreases from 350 to 218 days during 13 years, then remains almost constant for about 10 years. Our study of radial velocities indicates a circular orbit for the binary and yields a mass ratio of 0.203 $\pm$ 0.001. From the analysis of the orbital light curve we find that the system contains 13.8 and 2.81 \msun\ stars of radii 8.8 and 12.6 \rsun\ and absolute bolometric magnitudes -6.4 and -3.0, respectively. The orbit semi-major axis is 49.9 \rsun\ and the stellar temperatures are 25460 K and 9825 K. We find evidence for an optically and geometrically thick disk around the hotter star. According to our model, the disk has a radius of 25 \rsun, central and outer vertical thickness of 1.6 \rsun\ and 3.5 \rsun, and temperature of 9380 K at its outer edge. Two shock regions located at roughly opposite parts of the outer disk rim can explain the light curves asymmetries. The system is a member of the double periodic variables and its relatively high-mass and long photometric cycle make it similar in some aspects to $\beta$ Lyrae., Comment: Accepted for publication in MNRAS main journal
Published: 2019
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34. Optical phase curve of the ultra-hot Jupiter WASP-121b

Author: Stéphane Udry, Kevin Heng, H. Giles, Romain Allart, David Ehrenreich, Sara Seager, Daniel Kitzmann, C. Melo, Vincent Bourrier, Jon M. Jenkins, Francesco Pepe, M. Cretignier, Roland Vanderspek, Mark E. Rose, Valerio Nascimbeni, Douglas A. Caldwell, Lorenzo Pino, Xavier Dumusque, Baptiste Lavie, C. Lovis, T. Kuntzer, Monika Lendl, Aurélien Wyttenbach, Heather M. Cegla, Christopher E. Henze, Damien Ségransan, H. J. Hoeijmakers, Nicola Astudillo-Defru, A. Suarez-Mascareno, George R. Ricker, and Felipe Murgas
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, Phase curve, 01 natural sciences, Photometry (optics), Wavelength, 13. Climate action, Space and Planetary Science, 0103 physical sciences, Hot Jupiter, Hotspot (geology), Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Black-body radiation, Emission spectrum, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the analysis of TESS optical photometry of WASP-121b, which reveal the phase curve of this transiting ultra-hot Jupiter. Its hotspot is located at the substellar point, showing inefficient heat transport from the dayside (2870 K) to the nightside ($, Comment: 11 pages, 5 figures, submitted to A&A
Published: 2019
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35. GJ 1252 b: A 1.2 R ⊕ Planet Transiting an M3 Dwarf at 20.4 pc

Author: Enric Palle, Roland Vanderspek, J. M. Irwin, Sébastien Leépine, Sara Seager, Maximilian N. Günther, J. Villasenor, Eric L. N. Jensen, Ramotholo Sefako, David W. Latham, R. Cloutier, David Charbonneau, John F. Kielkopf, Avi Shporer, K. I. Collins, Tianjun Gan, Knicole D. Colón, James D. Armstrong, Thiam-Guan Tan, Tansu Daylan, Jon M. Jenkins, Courtney D. Dressing, Joshua N. Winn, Elisabeth Matthews, Philip S. Muirhead, Chelsea X. Huang, Keivan G. Stassun, Xavier Bonfils, Coel Hellier, Jennifer G. Winters, Andrew Vanderburg, Karen A. Collins, Nicola Astudillo-Defru, Mark E. Rose, Joseph D. Twicken, David R. Anderson, George R. Ricker, Keith Horne, Universidad Católica de la Santísima Concepción (UCSC), Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), School of Physics and Astronomy [Exeter], and University of Exeter
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy, Astronomy and Astrophysics, 01 natural sciences, Exoplanet, Photometry (astronomy), 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, QB600, QB799, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: We report the discovery of GJ 1252 b, a planet with a radius of 1.193 $\pm$ 0.074 $R_{\oplus}$ and an orbital period of 0.52 days around an M3-type star (0.381 $\pm$ 0.019 $M_{\odot}$, 0.391 $\pm$ 0.020 $R_{\odot}$) located 20.385 $\pm$ 0.019 pc away. We use TESS data, ground-based photometry and spectroscopy, Gaia astrometry, and high angular resolution imaging to show that the transit signal seen in the TESS data must originate from a transiting planet. We do so by ruling out all false positive scenarios that attempt to explain the transit signal as originating from an eclipsing stellar binary. Precise Doppler monitoring also leads to a tentative mass measurement of 2.09 $\pm$ 0.56 $M_{\oplus}$. The host star proximity, brightness ($V$ = 12.19 mag, $K$ = 7.92 mag), low stellar activity, and the system's short orbital period make this planet an attractive target for detailed characterization, including precise mass measurement, looking for other objects in the system, and planet atmosphere characterization., Accepted to ApJ Letters
Published: 2020
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36. The 55 Cancri system reassessed

Author: Gregory W. Henry, C. Moutou, J. Rey, Nicola Astudillo-Defru, Björn Benneke, Vincent Bourrier, Xavier Dumusque, Caroline Dorn, C. Lovis, G. Hebrard, David Ehrenreich, Brice-Olivier Demory, University of Zurich, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Universität Zürich [Zürich] = University of Zurich (UZH), Tennessee State University, Universidad de Concepción [Chile], Université de Montréal (UdeM), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), University of Bern, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Université de Genève = University of Geneva (UNIGE), Universidad de Concepción - University of Concepcion [Chile], and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, 530 Physics, FOS: Physical sciences, Astrophysics, Rotation, 01 natural sciences, Atmosphere, [PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO], 1912 Space and Planetary Science, Planet, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Giant planet, Astronomy and Astrophysics, Radius, Photometry (astronomy), 13. Climate action, Space and Planetary Science, 10231 Institute for Computational Science, 3103 Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Planetary mass, Astrophysics - Earth and Planetary Astrophysics
Abstract: Orbiting a bright, nearby star the 55 Cnc system offers a rare opportunity to study a multiplanet system that has a wide range of planetary masses and orbital distances. Using two decades of photometry and spectroscopy data, we have measured the rotation of the host star and its solar-like magnetic cycle. Accounting for this cycle in our velocimetric analysis of the system allows us to revise the properties of the outermost giant planet and its four planetary companions. The innermost planet 55 Cnc e is an unusually close-in super-Earth, whose transits have allowed for detailed follow-up studies. Recent observations favor the presence of a substantial atmosphere yet its composition, and the nature of the planet, remain unknown. We combined our derived planet mass (Mp = 8.0+-0.3 Mearth) with refined measurement of its optical radius derived from HST/STIS observations (Rp = 1.88+-0.03 Rearth over 530-750nm) to revise the density of 55 Cnc e (rho = 6.7+-0.4 g cm-3). Based on these revised properties we have characterized possible interiors of 55 Cnc e using a generalized Bayesian model. We confirm that the planet is likely surrounded by a heavyweight atmosphere, contributing a few percents of the planet radius. While we cannot exclude the presence of a water layer underneath the atmosphere, this scenario is unlikely given the observations of the planet across the entire spectrum and its strong irradiation. Follow-up observations of the system in photometry and in spectroscopy over different time-scales are needed to further investigate the nature and origin of this iconic super-Earth., 22 pages, 16 figures, accepted for publication in A&A
Published: 2018
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37. The CARMENES search for exoplanets around M dwarfs A Neptune-mass planet traversing the habitable zone around HD 180617

Author: Stefan Dreizler, Víctor J. S. Béjar, A. Schweitzer, Carlos Cifuentes, Walter Seifert, S. Sadegi, Rafael Luque, Thomas Henning, E. W. Guenther, V. M. Passegger, E. Díez-Alonso, M. Lafarga, Trifon Trifonov, M. Perger, Michel Mayor, F. F. Bauer, M. Kürster, Stéphane Udry, Xavier Bonfils, J. Colomé, Jose A. Caballero, X. Delfosse, Andreas Quirrenbach, M. Zechmeister, Artie P. Hatzes, Nicola Astudillo-Defru, S. V. Jeffers, Ansgar Reiners, S. Pedraz, Sabine Reffert, Ignasi Ribas, M. Cortés-Contreras, D. Montes, Otmar Stahl, Pedro J. Amado, Juan Carlos Morales, Lev Tal-Or, T. Forveille, A. Kaminski, Holger Mandel, CSIC - Instituto de Astrofísica de Andalucía (IAA), Landessternwarte Königstuhl, CSIC - Instituto de Ciencias del Espacio (ICE), University of Göttingen, Thüringer Landessternwarte Tautenburg Karl Schwarzschild-Observatorium, Instituto de Astrofísica de Canarias, CSIC-INTA - Centro de Astrobiología (CAB), Ministerio de Economía y Competitividad (España), German Research Foundation, Klaus Tschira Foundation, Ministry of Science, Research and Art Baden-Württemberg, CSIC-Junta de Extremadura - Instituto de Arqueología (IAM), Universidad Complutense de Madrid, Max Planck Society, Consejo Superior de Investigaciones Científicas (España), European Commission, and Max Planck Institute for Astronomy
Subjects: Astrofísica, Proper motion, 010504 meteorology & atmospheric sciences, Doppler spectroscopy, FOS: Physical sciences, Astrophysics, Stars: late-type, 7. Clean energy, 01 natural sciences, Neptune, Planet, low-mass [Stars], 0103 physical sciences, Stars: low-mass, 010303 astronomy & astrophysics, Stars: individual: HD 180617, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Astronomy and Astrophysics, Planetary system, individual: HD 180617 [Stars], Exoplanet, Radial velocity, Astronomía, Planetary systems, 13. Climate action, Space and Planetary Science, late-type [Stars], Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics
Abstract: Michel Mayor (Nobel de Física 2019 por el descubrimiento del primer planeta extrasolar), Despite their activity, low-mass stars are of particular importance for the search of exoplanets by the means of Doppler spectroscopy, as planets with lower masses become detectable. We report on the discovery of a planetary companion around HD 180617, a bright (J = 5.58 mag), low-mass (M = 0.45M) star of spectral type M2.5 V. The star, located at a distance of 5.9 pc, is the primary of the high proper motion binary system containing vB 10, a star with one of the lowest masses known in most of the twentieth century. Our analysis is based on new radial velocity (RV) measurements made at red-optical wavelengths provided by the high-precision spectrograph CARMENES, which was designed to carry out a survey for Earth-like planets around M dwarfs. The available CARMENES data are augmented by archival Doppler measurements from HIRES and HARPS. Altogether, the RVs span more than 16 yr. The modeling of the RV variations, with a semi-amplitude of K = 2.85-0.25 +0.16 m s-1, yields a Neptune-like planet with a minimum mass of 12.2-1.4 +1.0 M on a 105.90-0.10 +0.09 d circumprimary orbit, which is partly located in the host star's habitable zone. The analysis of time series of common activity indicators does not show any dependence on the detected RV signal. The discovery of HD 180617 b not only adds information to a currently hardly filled region of the mass-period diagram of exoplanets around M dwarfs, but the investigated system becomes the third known binary consisting of M dwarfs and hosting an exoplanet in an S-type configuration. Its proximity makes it an attractive candidate for future studies. © ESO 2018., CARMENES is an instrument for the Centro Astronómico Hispano-Alemán de Calar Alto (CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de Investigaciones Científicas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, Landessternwarte Königstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen, Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg, Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astrobiología and Centro Astronómico Hispano-Alemán), with additional contributions by the Spanish Ministry of Science through projects AYA2016-79425-C3-1/2/3-P, ESP2016-80435-C2-1-R, and AYA2015-69350-C3-2-P, the German Science Foundation through the Major Research Instrumentation Programme and DFG Research Unit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, the states of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.
Published: 2018

38. The SOPHIE search for northern extrasolar planets XIII. Two planets around M-dwarfs Gl617A and Gl96

Author: Nathan Hara, T. Lopez, Isabelle Boisse, X. Delfosse, B. Courcol, Luc Arnold, Xavier Dumusque, Francesco Pepe, Nuno C. Santos, Damien Ségransan, Simon Borgniet, Magali Deleuil, O. Mousis, Xavier Bonfils, M. J. Hobson, B. Brugger, Flavien Kiefer, L. Mignon, Paul Wilson, Nicola Astudillo-Defru, Alexandre Santerne, N. Cabrera, Rodrigo F. Díaz, S. Dalal, François Bouchy, J. Rey, M. Stalport, Olivier Demangeon, T. Forveille, David Ehrenreich, Guillaume Hébrard, G. Montagnier, C. Moutou, Stéphane Udry, Vincent Bourrier, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Universidad de Concepción [Chile], Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatoire de Haute-Provence (OHP), Institut Pythéas (OSU PYTHEAS), Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), AstroParticule et Cosmologie (APC (UMR_7164)), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Université Paris-Sud - Paris 11 (UP11), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Laboratoire de Génie de la Conception (LGeco), Institut National des Sciences Appliquées - Strasbourg (INSA Strasbourg), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción - University of Concepcion [Chile], Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Université de Genève = University of Geneva (UNIGE), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7), and Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Ciencias Físicas, Late-Type [Stars], media_common.quotation_subject, FOS: Physical sciences, Minimum mass, Individual: Gl96 [Stars], Context (language use), Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, purl.org/becyt/ford/1 [https], Planet, Individual: Gl617a [Stars], 0103 physical sciences, Planetary Systems, Astrophysics::Solar and Stellar Astrophysics, Eccentricity (behavior), 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, media_common, Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010308 nuclear & particles physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, Radial Velocities [Techniques], purl.org/becyt/ford/1.3 [https], Exoplanet, Astronomía, Radial velocity, Stars, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Circumstellar habitable zone, CIENCIAS NATURALES Y EXACTAS, Astrophysics - Earth and Planetary Astrophysics
Abstract: We report the detection of two exoplanets and a further tentative candidate around the M-dwarf stars Gl96 and Gl617A, based on radial velocity measurements obtained with the SOPHIE spectrograph at the Observatoire de Haute-Provence. Both stars were observed in the context of the SOPHIE exoplanet consortium's dedicated M-dwarf subprogramme, which aims to detect exoplanets around nearby M-dwarf stars through a systematic survey. For Gl96, we present the discovery of a new exoplanet at 73.9 d with a minimum mass of 19.66 earth masses. Gl96 b has an eccentricity of 0.44, placing it among the most eccentric planets orbiting M stars. For Gl617A we independently confirm a recently reported exoplanet at 86.7 d with a minimum mass of 31.29 earth masses. Both Gl96 b and Gl617A b are potentially within the habitable zone, though Gl96 b's high eccentricity may take it too close to the star at periapsis., 22 pages, 23 figures
Published: 2018
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39. A temperate exo-Earth around a quiet M dwarf at 3.4 parsec

Author: T. Forveille, Felipe Murgas, Nuno C. Santos, C. Lovis, Damien Ségransan, J. M. Almenara, Francesco Pepe, Nicola Astudillo-Defru, Rodrigo F. Díaz, Xavier Bonfils, A. Wunsche, X. Delfosse, Stéphane Udry, M. Mayor, François Bouchy, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción [Chile], Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institut d'Astrophysique de Paris (IAP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto [Porto], Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), and Universidade do Porto
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Physics, 010504 meteorology & atmospheric sciences, media_common.quotation_subject, Giant planet, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Orbital period, Light curve, 01 natural sciences, Radial velocity, Stars, 13. Climate action, Space and Planetary Science, Sky, Planet, [SDU]Sciences of the Universe [physics], 0103 physical sciences, planetary systems - stars: late-type - techniques: radial velocities, 010303 astronomy & astrophysics, Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences, media_common
Abstract: The combination of high-contrast imaging and high-dispersion spectroscopy, which has successfully been used to detect the atmosphere of a giant planet, is one of the most promising potential probes of the atmosphere of Earth-size worlds. The forthcoming generation of extremely large telescopes (ELTs) may obtain sufficient contrast with this technique to detect O$_2$ in the atmosphere of those worlds that orbit low-mass M dwarfs. This is strong motivation to carry out a census of planets around cool stars for which habitable zones can be resolved by ELTs, i.e. for M dwarfs within $\sim$5 parsecs. Our HARPS survey has been a major contributor to that sample of nearby planets. Here we report on our radial velocity observations of Ross 128 (Proxima Virginis, GJ447, HIP 57548), an M4 dwarf just 3.4 parsec away from our Sun. This source hosts an exo-Earth with a projected mass $m \sin i = 1.35 M_\oplus$ and an orbital period of 9.9 days. Ross 128 b receives $\sim$1.38 times as much flux as Earth from the Sun and its equilibrium ranges in temperature between 269 K for an Earth-like albedo and 213 K for a Venus-like albedo. Recent studies place it close to the inner edge of the conventional habitable zone. An 80-day long light curve from K2 campaign C01 demonstrates that Ross~128~b does not transit. Together with the All Sky Automated Survey (ASAS) photometry and spectroscopic activity indices, the K2 photometry shows that Ross 128 rotates slowly and has weak magnetic activity. In a habitability context, this makes survival of its atmosphere against erosion more likely. Ross 128 b is the second closest known exo-Earth, after Proxima Centauri b (1.3 parsec), and the closest temperate planet known around a quiet star. The 15 mas planet-star angular separation at maximum elongation will be resolved by ELTs ($>$ 3$\lambda/D$) in the optical bands of O$_2$., Comment: A&A (Received 20 September 2017 / Accepted 26 October 2017)
Published: 2018
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40. Optical and Near-Infrared Radial Velocity Content of M Dwarfs: Testing Models with Barnard's Star

Author: Étienne Artigau, Pedro Figueira, Nicola Astudillo-Defru, Lison Malo, Xavier Delfosse, and René Doyon
Subjects: Physics, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Luminosity, 010309 optics, Radial velocity, Stars, Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Hot Jupiter, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Circumstellar habitable zone, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics
Abstract: High precision radial velocity (RV) measurements have been central in the study of exoplanets during the last two decades, from the early discovery of hot Jupiters, to the recent mass measurements of Earth-sized planets uncovered by transit surveys. While optical radial-velocity is now a mature field, there is currently a strong effort to push the technique into the near-infrared (nIR) domain (chiefly $Y$, $J$, $H$ and $K$ band passes) to probe planetary systems around late-type stars. The combined lower mass and luminosity of M dwarfs leads to an increased reflex RV signal for planets in the habitable zone compared to Sun-like stars. The estimates on the detectability of planets rely on various instrumental characteristics, but also on a prior knowledge of the stellar spectrum. While the overall properties of M dwarf spectra have been extensively tested against observations, the same is not true for their detailed line profiles, which leads to significant uncertainties when converting a given signal-to-noise ratio to a corresponding RV precision as attainable on a given spectrograph. By combining archival CRIRES and HARPS data with ESPaDOnS data of Barnard's star, we show that state-of-the-art atmosphere models over-predict the $Y$ and $J$-band RV content by more than a factor of $\sim$$2$, while under-predicting the $H$ and $K$-band content by half., accepted for publication in AJ
Published: 2018

41. Eyes on K2-3: A system of three likely sub-Neptunes characterized with HARPS-N and HARPS

Author: Nuno C. Santos, Giampaolo Piotto, Damien Ségransan, David F. Phillips, Andrew Vanderburg, L. Di Fabrizio, Courtney D. Dressing, Riccardo Smareglia, Luigi Mancini, David Charbonneau, Francesco Pepe, Antonio Maggio, Valerio Nascimbeni, Annelies Mortier, E. Poretti, Mercedes López-Morales, Gaetano Scandariato, Ilaria Carleo, R. Cosentino, Andrew Collier Cameron, Ken Rice, Stéphane Udry, Pedro Figueira, Michel Mayor, Andrea Bignamini, M. Esposito, S. Masiero, Giuseppe Leto, Jonathan Irwin, E. González-Álvarez, Serena Benatti, Alessandro Sozzetti, X. Delfosse, Rim Fares, F. Borsa, Fatemeh Motalebi, A. Wünsche, J. Maldonado, Monica Rainer, X. Bonfils, T. Forveille, Christopher A. Watson, Mario Damasso, Eric D. Lopez, F. Bouchy, Christophe Lovis, Dimitar Sasselov, Aldo S. Bonomo, Jose-Manuel Almenara, Emilio Molinari, Riccardo Claudi, Isabella Pagano, E. Covino, Silvano Desidera, K. Biazzo, Raphaëlle D. Haywood, Giuseppina Micela, David W. Latham, Felipe Murgas, Raffaele Gratton, Lars A. Buchhave, Ararat Harutyunyan, J. Asher Johnson, P. Giacobbe, Aldo F. M. Fiorenzano, Luca Malavolta, Li Zeng, Nicola Astudillo-Defru, A. F. Lanza, Laura Affer, INAF - Osservatorio Astrofisico di Torino (OATo), Istituto Nazionale di Astrofisica (INAF), Universidad de Concepción [Chile], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Osaka City University Advanced Mathematical Institute (OCAMI), Osaka Media Center, University of Granada/Dept of Paediatrics, University of Granada [Granada], INAF - Osservatorio Astrofisico di Catania (OACT), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, INAF - Osservatorio Astrofisico di Arcetri (OAA), Institut d'Astrophysique de Paris (IAP), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), University of St Andrews [Scotland], INAF - Osservatorio Astronomico di Padova (OAPD), Telescopio Nazionale Galileo (TNG), RN, Sciences pour l'environnement (SPE), Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP), Laboratoire Astrophysique de Toulouse-Tarbes (LATT), Centre National de la Recherche Scientifique (CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto, Institut de Mathématiques de Toulouse UMR5219 (IMT), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Osserv Astrofis Catania, Ist Nazl Astrofis, Harvard-Smithsonian Center for Astrophysics (CfA), Smithsonian Institution-Harvard University [Cambridge], Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), INAF - Osservatorio Astronomico di Palermo (OAPa), INAF - Osservatorio Astronomico di Brera (OAB), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS)-Université Pascal Paoli (UPP)-Centre National de la Recherche Scientifique (CNRS), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Universidade do Porto [Porto], Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse 1 Capitole (UT1)-Université Toulouse - Jean Jaurès (UT2J)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Harvard University [Cambridge]-Smithsonian Institution, Osservatorio Astronomico di Brera, Osaka City university Advanced Mathematical Institute [Osaka] (OCAMI), Osaka City University (OCU), European Commission, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Universidad de Concepción - University of Concepcion [Chile], SUPA School of Physics and Astronomy [University of St Andrews], University of St Andrews [Scotland]-Scottish Universities Physics Alliance (SUPA), Universidad de Granada = University of Granada (UGR), Università degli Studi di Padova = University of Padua (Unipd), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Universidade do Porto = University of Porto, Université Toulouse Capitole (UT Capitole), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Harvard University-Smithsonian Institution, and Université de Genève = University of Geneva (UNIGE)
Subjects: individual: K2-3 [stars], planets and satellites: detection, detection [planets and satellites], fundamental parameters [Planets and satellites], FOS: Physical sciences, Astrophysics, stars: individual: 2MASS 11292037-0127173, 01 natural sciences, individual: EPIC 201367065 [stars], Settore FIS/05 - Astronomia e Astrofisica, Planet, 0103 physical sciences, techniques: radial velocities, QB Astronomy, stars: individual: K2-3, composition [planets and satellites], 010303 astronomy & astrophysics, QC, QB, individual: 2MASS 11292037-0127173 [stars], Earth and Planetary Astrophysics (astro-ph.EP), Physics, stars: individual: EPIC 201367065, Planetary habitability, 010308 nuclear & particles physics, Stellar rotation, planets and satellites: composition, radial velocities [techniques], Astronomy and Astrophysics, 3rd-DAS, Orbital period, Radial velocity, Stars, individual: K2-3 (2MASS 11292037-0127173, EPIC 201367065) [Stars], QC Physics, Amplitude, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Astrophysics::Earth and Planetary Astrophysics, Circumstellar habitable zone, Astrophysics - Earth and Planetary Astrophysics
Abstract: M-dwarf stars are promising targets for identifying and characterizing potentially habitable planets. K2-3 is a nearby (45 pc), early-type M dwarf hosting three small transiting planets, the outermost of which orbits close to the inner edge of the stellar (optimistic) habitable zone. The K2-3 system is well suited for follow-up characterization studies aimed at determining accurate masses and bulk densities of the three planets. Using a total of 329 radial velocity measurements collected over 2.5 years with the HARPS-N and HARPS spectrographs and a proper treatment of the stellar activity signal, we aim to improve measurements of the masses and bulk densities of the K2-3 planets. We use our results to investigate the physical structure of the planets. We analyse radial velocity time series extracted with two independent pipelines by using Gaussian process regression. We adopt a quasi-periodic kernel to model the stellar magnetic activity jointly with the planetary signals. We use Monte Carlo simulations to investigate the robustness of our mass measurements of K2-3\,c and K2-3\,d, and to explore how additional high-cadence radial velocity observations might improve them. Despite the stellar activity component being the strongest signal present in the radial velocity time series, we are able to derive masses for both planet b ($M_{\rm b}=6.6\pm1.1$ $M_{\rm \oplus}$) and planet c ($M_{\rm c}=3.1^{+1.3}_{-1.2}$ $M_{\rm \oplus}$). The Doppler signal due to K2-3\,d remains undetected, likely because of its low amplitude compared to the radial velocity signal induced by the stellar activity. The closeness of the orbital period of K2-3\,d to the stellar rotation period could also make the detection of the planetary signal complicated. [...], 14 pages, 15 figures, accepted for publication in A&A
Published: 2018
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42. Extrasolar planets and brown dwarfs around AF-type stars. X.The SOPHIE northern sample. Combining the SOPHIE and HARPS surveys to compute the close giant planet mass-period distribution around AF-type stars

Author: R. da Silva, Nuno C. Santos, B. Loeillet, C. Lovis, D. Queloz, Damien Ségransan, A. Eggenberger, Guillaume Hébrard, François Bouchy, Anne-Marie Lagrange, G. Montagnier, J. P. Sivan, T. Forveille, J. L. Beuzit, K. Debondt, Isabelle Boisse, Rodrigo F. Díaz, Stéphane Udry, David Ehrenreich, Nicola Astudillo-Defru, C. Moutou, M. Deleuil, X. Bonfils, Luc Arnold, Francesco Pepe, Alfred Vidal-Madjar, Frederic Pont, F. Galland, N. Meunier, M. Desort, C. Perrier, X. Delfosse, Alexandre Santerne, S. Borgniet, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), Institut Pythéas (OSU PYTHEAS), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Centre National de la Recherche Scientifique (CNRS), Universidad de Concepción [Chile], Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Institut d'Astrophysique de Paris (IAP), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Canada-France-Hawaii Telescope Corporation (CFHT), National Research Council of Canada (NRC)-Centre National de la Recherche Scientifique (CNRS)-University of Hawai'i [Honolulu] (UH), Cavendish Laboratory, University of Cambridge [UK] (CAM), Universidade do Porto [Porto], Istituto Nazionale di Astrofisica (INAF), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Universidad de Concepción - University of Concepcion [Chile], Université de Genève = University of Geneva (UNIGE), Universidade do Porto = University of Porto, Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), and Universidade do Porto
Subjects: Stellar mass, Population, Brown dwarf, FOS: Physical sciences, Astrophysics, 01 natural sciences, 0103 physical sciences, education, 010303 astronomy & astrophysics, planetary systems, Physics, Earth and Planetary Astrophysics (astro-ph.EP), education.field_of_study, 010308 nuclear & particles physics, Giant planet, Astronomy and Astrophysics, Planetary system, stars: early-type, Exoplanet, Radial velocity, stars: variables: general, Stars, 13. Climate action, Space and Planetary Science, echniques: radial velocities, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary Astrophysics
Abstract: The impact of the stellar mass on the giant planet properties is still to be fully understood. Main-Sequence (MS) stars more massive than the Sun remain relatively unexplored in radial velocity (RV) surveys, due to their characteristics that hinder classical RV measurements. Our aim is to characterize the close (up to 2.5 au) giant planet (GP) and brown dwarf (BD) population around AF MS stars and compare this population to stars with different masses. We used the SOPHIE spectrograph located on the 1.93m telescope at Observatoire de Haute-Provence to observe 125 northern, MS AF dwarfs. We used our dedicated SAFIR software to compute the RV and other spectroscopic observables. We characterized the detected sub-stellar companions and computed the GP and BD occurrence rates combining the present SOPHIE survey and a similar HARPS survey. We present new data on two known planetary systems around the F5-6V dwarfs HD16232 and HD113337. For the latter, we report an additional RV variation that might be induced by a second GP on a wider orbit. We also report the detection of fifteen binaries or massive sub-stellar companions with high-amplitude RV variations or long-term RV trends. Based on 225 targets observed with SOPHIE or HARPS, we constraint the BD frequency within 2-3 au around AF stars to be below 4 percents (1-sigma). For Jupiter-mass GP within 2-3 au (periods below 1000 days), we found the occurrence rate to be 3.7 (+3/-1) percents around AF stars with masses below 1.5 solar masses, and to be below 6 percents around AF stars with masses above 1.5 solar masses. For periods smaller than 10 days, we find the GP occurrence rate to be below 3 or 4.5 percents, respectively. Our results are compatible with the GP frequency reported around FGK dwarfs and are compatible with a possible increase of GP orbital periods with the stellar mass as predicted by formation models., Comment: 32 pages, 21 figures. Accepted to Astronomy & Astrophysics on August 30, 2018
Published: 2018
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43. A temperate rocky super-Earth transiting a nearby cool star

Author: Nuno C. Santos, X. Delfosse, Gilbert A. Esquerdo, Jonathan Irwin, François Bouchy, T. Forveille, Jennifer G. Winters, A. Wunsche, David Charbonneau, Stéphane Udry, Raphaëlle D. Haywood, Courtney D. Dressing, Joseph E. Rodriguez, Jason A. Dittmann, Thiam-Guan Tan, Xavier Bonfils, Elisabeth R. Newton, David W. Latham, Christophe Lovis, Nicola Astudillo-Defru, Francesco Pepe, Zachory K. Berta-Thompson, Felipe Murgas, J. M. Almenara, Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Laboratoire d'Astrophysique de Marseille (LAM), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, Kepler-69c, FOS: Physical sciences, Planets, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Stars, Celestial, Planet, Exobiology, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Discoveries of exoplanets, Earth and Planetary Astrophysics (astro-ph.EP), Physics, Multidisciplinary, Super-Earth, Kepler-22b, Temperature, Water, Astronomy, Habitability of orange dwarf systems, Exoplanet, [SDU]Sciences of the Universe [physics], 13. Climate action, Astrophysics::Earth and Planetary Astrophysics, Kepler-20f, Astrophysics - Earth and Planetary Astrophysics
Abstract: M dwarf stars, which have masses less than 60 per cent that of the Sun, make up 75 per cent of the population of the stars in the Galaxy [1]. The atmospheres of orbiting Earth-sized planets are observationally accessible via transmission spectroscopy when the planets pass in front of these stars [2,3]. Statistical results suggest that the nearest transiting Earth-sized planet in the liquid-water, habitable zone of an M dwarf star is probably around 10.5 parsecs away [4]. A temperate planet has been discovered orbiting Proxima Centauri, the closest M dwarf [5], but it probably does not transit and its true mass is unknown. Seven Earth-sized planets transit the very low-mass star TRAPPIST-1, which is 12 parsecs away [6,7], but their masses and, particularly, their densities are poorly constrained. Here we report observations of LHS 1140b, a planet with a radius of 1.4 Earth radii transiting a small, cool star (LHS 1140) 12 parsecs away. We measure the mass of the planet to be 6.6 times that of Earth, consistent with a rocky bulk composition. LHS 1140b receives an insolation of 0.46 times that of Earth, placing it within the liquid-water, habitable zone [8]. With 90 per cent confidence, we place an upper limit on the orbital eccentricity of 0.29. The circular orbit is unlikely to be the result of tides and therefore was probably present at formation. Given its large surface gravity and cool insolation, the planet may have retained its atmosphere despite the greater luminosity (compared to the present-day) of its host star in its youth [9,10]. Because LHS 1140 is nearby, telescopes currently under construction might be able to search for specific atmospheric gases in the future [2,3]., 25 Pages, 2 Figures, 1 Table, 8 Extended Data Figures, Published in Nature on April 20, 2017
Published: 2017
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44. The HARPS search for southern extra-solar planets XLI. A dozen planets around the M dwarfs GJ 3138, GJ 3323, GJ 273, GJ 628, and GJ 3293

Author: Michel Mayor, Stéphane Udry, C. Lovis, Xavier Bonfils, Nuno C. Santos, Damien Ségransan, Francesco Pepe, François Bouchy, A. Wünsche, X. Delfosse, T. Forveille, Nicola Astudillo-Defru, and Felipe Murgas
Subjects: Orbital elements, Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy and Astrophysics, Context (language use), Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Radial velocity, Space and Planetary Science, Planet, 0103 physical sciences, Terrestrial planet, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Circumstellar habitable zone, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: Context. Low mass stars are currently the best targets for searches for rocky planets in the habitable zone of their host star. Over the last 13 years, precise radial velocities measured with the HARPS spectrograph have identified over a dozen super-Earths and Earth-mass planets (msin i, 19 pages, 24 figures. Astronomy and Astrophysics in press
Published: 2017
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45. The SOPHIE search for northern extrasolar planets XII. Three giant planets suitable for astrometric mass determination with Gaia

Author: Claire Moutou, Vincent Bourrier, S. Borgniet, David Ehrenreich, Xavier Delfosse, Nicola Astudillo-Defru, B. Courcol, Paul Wilson, François Bouchy, Alexandre Santerne, Xavier Bonfils, Luc Arnold, Francesco Pepe, Olivier Demangeon, Magali Deleuil, Thierry Forveille, Guillaume Hébrard, Maxime Marmier, Isabelle Boisse, J. Rey, Rodrigo F. Díaz, Stéphane Udry, Nuno C. Santos, Damien Ségransan, Johannes Sahlmann, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)
Subjects: 010504 meteorology & atmospheric sciences, Ciencias Físicas, BROWN DWARFS, FOS: Physical sciences, RADIAL VELOCITIES [TECHNIQUES], 01 natural sciences, INDIVIDUAL: HD42012 [STARS], law.invention, purl.org/becyt/ford/1 [https], Telescope, law, Observatory, Planet, 0103 physical sciences, PLANETARY SYSTEMS, INDIVIDUAL: HD29021 [STARS], Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Spectrograph, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy, Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Astrometry, Exoplanet, Astronomía, Radial velocity, Stars, Space and Planetary Science, INDIVIDUAL: HD17674 [STARS], Astrophysics::Earth and Planetary Astrophysics, CIENCIAS NATURALES Y EXACTAS, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present new radial velocity measurements for three low-metallicity solar-like stars observed with the SOPHIE spectrograph and its predecessor ELODIE, both installed at the 193 cm telescope of the Haute-Provence Observatory, allowing the detection and characterization of three new giant extrasolar planets in intermediate periods of 1.7 to 3.7 years. All three stars, HD17674, HD42012 and HD29021 present single giant planetary companions with minimum masses between 0.9 and 2.5 MJup. The range of periods and masses of these companions, along with the distance of their host stars, make them good targets to look for astrometric signals over the lifetime of the new astrometry satellite Gaia. We discuss the preliminary astrometric solutions obtained from the first Gaia data release., Accepted for publication in A&A. 14 pages, 6 figures, 7 tables
Published: 2017
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46. The HARPS search for southern extra-solar planets XLII. A system of Earth-mass planets around the nearby M dwarf YZ Ceti

Author: J.-B. Delisle, X. Delfosse, Xavier Bonfils, Rodrigo F. Díaz, Felipe Murgas, Nicola Astudillo-Defru, Nuno C. Santos, Damien Ségransan, Francesco Pepe, Stéphane Udry, A. Wünsche, C. Lovis, Jose-Manuel Almenara, François Bouchy, Michel Mayor, and T. Forveille
Subjects: 010504 meteorology & atmospheric sciences, Ciencias Físicas, FOS: Physical sciences, RADIAL VELOCITIES [TECHNIQUES], Astrophysics, LATE-TYPE [STARS], 01 natural sciences, purl.org/becyt/ford/1 [https], Photometry (optics), INDIVIDUAL: YZ CET [STARS], Planet, 0103 physical sciences, PLANETARY SYSTEMS, Spectroscopy, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Astronomy and Astrophysics, purl.org/becyt/ford/1.3 [https], Planetary system, Earth mass, Exoplanet, Astronomía, Radial velocity, Stars, Space and Planetary Science, CIENCIAS NATURALES Y EXACTAS, Astrophysics - Earth and Planetary Astrophysics
Abstract: Exoplanet surveys have shown that systems with multiple low-mass planets on compact orbits are common. Except for few cases, however, the masses of these planets are generally unknown. At the very end of the main sequence, host stars have the lowest mass and hence offer the largest reflect motion for a given planet. In that context, we monitored the low-mass (0.13Msun) M dwarf YZ Cet (GJ 54.1, HIP 5643) intensively and obtained both radial velocities and stellar-activity indicators derived from both spectroscopy and photometry. We find strong evidence that it is orbited by at least three planets in compact orbits (P=1.97, 3.06, 4.66 days), with the inner two near a 2:3 mean-motion resonance. The minimum masses are comparable to that of Earth (Msini=0.75+-0.13, 0.98+-0.14, and 1.14+-0.17 Mearth) and also the lowest masses measured by radial velocity so far. We note the possibility for an even lower-mass, fourth planet with Msini=0.472+-0.096 Mearth at P=1.04 days. An n-body dynamical model is used to put further constraints on the system parameters. At 3.6 parsecs, YZ Cet is the nearest multi-planet system detected to date., Comment: 7 pages, 4 figures, accepted for publication in Astronomy & Astrophysics Letters
Published: 2017
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47. Characterization of the K2-18 multi-planetary system with HARPS: A habitable zone super-Earth and discovery of a second, warm super-Earth on a non-coplanar orbit

Author: Felipe Murgas, A. Wünsche, Ryan Cloutier, Nuno C. Santos, Kristen Menou, Nicola Astudillo-Defru, Björn Benneke, X. Delfosse, C. Lovis, Jose-Manuel Almenara, Xavier Bonfils, René Doyon, David Ehrenreich, T. Forveille, Michel Mayor, Jason F. Rowe, Francesco Pepe, François Bouchy, and Stéphane Udry
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), Solar System, Super-Earth, 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, 01 natural sciences, Exoplanet, Radial velocity, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Ocean planet, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Circumstellar habitable zone, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: The bright M dwarf K2-18 at 34 pc is known to host a transiting super-Earth-sized planet orbiting within the star's habitable zone; K2-18b. Given the superlative nature of this system for studying an exoplanetary atmosphere receiving similar levels of insolation as the Earth, we aim to characterize the planet's mass which is required to interpret atmospheric properties and infer the planet's bulk composition. We obtain precision radial velocity measurements with the HARPS spectrograph and couple those measurements with the K2 photometry to jointly model the observed radial velocity variation with planetary signals and a radial velocity jitter model based on Gaussian process regression. We measure the mass of K2-18b to be $8.0 \pm 1.9$ M$_{\oplus}$ with a bulk density of $3.7 \pm 0.9$ g/cm$^3$ which may correspond to a predominantly rocky planet with a significant gaseous envelope or an ocean planet with a water mass fraction $\gtrsim 50$%. We also find strong evidence for a second, warm super-Earth K2-18c at $\sim 9$ days with a semi-major axis 2.4 times smaller than the transiting K2-18b. After re-analyzing the available light curves of K2-18 we conclude that K2-18c is not detected in transit and therefore likely has an orbit that is non-coplanar with K2-18b. A suite of dynamical integrations with varying simulated orbital eccentricities of the two planets are used to further constrain each planet's eccentricity posterior from which we measure $e_b < 0.43$ and $e_c < 0.47$ at 99% confidence. The discovery of the inner planet K2-18c further emphasizes the prevalence of multi-planet systems around M dwarfs. The characterization of the density of K2-18b reveals that the planet likely has a thick gaseous envelope which along with its proximity to the Solar system makes the K2-18 planetary system an interesting target for the atmospheric study of an exoplanet receiving Earth-like insolation., 13 pages, 8 figures including 4 interactive figures best viewed in Adobe Acrobat. Submitted to Astronomy & Astrophysics. Comments welcome
Published: 2017
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48. Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS) I. Detection of hot neutral sodium at high altitudes on WASP‐49b

Author: C. Lovis, David Ehrenreich, Damien Ségransan, Lorenzo Pino, Stéphane Udry, Alexandre Santerne, Francesco Pepe, Kevin Heng, Nicola Astudillo-Defru, Aurélien Wyttenbach, C. Melo, Heather M. Cegla, Baptiste Lavie, Felipe Murgas, Vincent Bourrier, Romain Allart, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, 01 natural sciences, Spectral line, Atmosphere, Planet, 0103 physical sciences, Hot Jupiter, Astrophysics::Solar and Stellar Astrophysics, Transit (astronomy), Spectroscopy, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Radius, Exoplanet, 3. Good health, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Earth and Planetary Astrophysics
Abstract: High-resolution optical spectroscopy during the transit of HD 189733b, a prototypical hot Jupiter, allowed the resolution of the Na I D sodium lines in the planet, giving access to the extreme conditions of the planet upper atmosphere. We have undertaken HEARTS, a spectroscopic survey of exoplanet upper atmospheres, to perform a comparative study of hot gas giants and determine how stellar irradiation affect them. Here, we report on the first HEARTS observations of the hot Saturn-mass planet WASP-49b. We observed the planet with the HARPS high-resolution spectrograph at ESO 3.6m telescope. We collected 126 spectra of WASP-49, covering three transits of WASP-49b. We analyzed and modeled the planet transit spectrum, while paying particular attention to the treatment of potentially spurious signals of stellar origin. We spectrally resolve the Na I D lines in the planet atmosphere and show that these signatures are unlikely to arise from stellar contamination. The large contrasts of $2.0\pm0.5\%$ (D$_2$) and $1.8\pm0.7\%$ (D$_1$) require the presence of hot neutral sodium ($2,950^{+400}_{-500}$ K) at high altitudes ($\sim$1.5 planet radius or $\sim$45,000 km). From estimating the cloudiness index of WASP-49b, we determine its atmosphere to be cloud free at the altitudes probed by the sodium lines. WASP-49b is close to the border of the evaporation desert and exhibits an enhanced thermospheric signature with respect to a farther-away planet such as HD 189733b., Accepted for publication in A&A. 14 pages
Published: 2017
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49. Detection and characterisation of 54 massive companions with the SOPHIE spectrograph

Author: M. J. Hobson, S. Borgniet, Vincent Bourrier, Isabelle Boisse, Nuno C. Santos, C. Lovis, Damien Ségransan, S. Dalal, T. Forveille, C. Perrier, G. Montagnier, M. Mayor, Janis Hagelberg, Nathan Hara, S. G. Sousa, Luc Arnold, Johannes Sahlmann, Alfred Vidal-Madjar, A. Santerne, Francesco Pepe, Guillaume Hébrard, Rodrigo F. Díaz, Jean-Luc Beuzit, Stéphane Udry, Flavien Kiefer, François Bouchy, C. Moutou, Paul Wilson, X. Delfosse, Olivier Demangeon, David Ehrenreich, J. Rey, Gregory W. Henry, B. Courcol, Nicola Astudillo-Defru, Anne-Marie Lagrange, Magali Deleuil, and X. Bonfils
Subjects: Physics, 010308 nuclear & particles physics, Molecular cloud, Brown dwarf, Astronomy and Astrophysics, Context (language use), Astrophysics, Orbital period, 01 natural sciences, Radial velocity, Stars, Space and Planetary Science, Planet, 0103 physical sciences, Gravitational collapse, 010303 astronomy & astrophysics
Abstract: Context. Brown dwarfs (BD) are substellar objects intermediate between planets and stars with masses of ~13–80 MJ. While isolated BDs are most likely produced by gravitational collapse in molecular clouds down to masses of a few MJ, a non-negligible fraction of low-mass companions might be formed through the planet-formation channel in protoplanetary discs. The upper mass limit of objects formed within discs is still observationally unknown, the main reason being the strong dearth of BD companions at orbital periods shorter than 10 yr, also known as the BD desert. Aims. To address this question, we aim at determining the best statistics of companions within the 10–100 MJ mass regime and located closer than ~10 au to the primary star, while minimising observation and selection bias. Methods. We made extensive use of the radial velocity (RV) surveys of northern hemisphere FGK stars within 60 pc of the Sun, performed with the SOPHIE spectrograph at the Observatoire de Haute-Provence. We derived the Keplerian solutions of the RV variations of 54 sources. Public astrometric data of the HIPPARCOS and Gaia missions allowed us to constrain the masses of the companions for most sources. We introduce GASTON, a new method to derive inclination combining RVs and Keplerian and astrometric excess noise from Gaia DR1. Results. We report the discovery of 12 new BD candidates. For five of them, additional astrometric data led to a revision of their mass in the M-dwarf regime. Among the seven remaining objects, four are confirmed BD companions, and three others are likely also in this mass regime. Moreover, we report the detection of 42 M-dwarfs within the range of 90 MJ–0.52 M⊙. The resulting M sin i-P distribution of BD candidates shows a clear drop in the detection rate below 80-day orbital period. Above that limit, the BD desert appears rather wet, with a uniform distribution of the M sin i. We derive a minimum BD-detection frequency around Solar-like stars of 2.0 ± 0.5%.
Published: 2019
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50. Characterization of the L 98-59 multi-planetary system with HARPS

Author: Guillermo Torres, George R. Ricker, Nicolás T. Kurtovic, Francesco Pepe, Sara Seager, Rodrigo F. Díaz, Philip S. Muirhead, Z. M. Berdinas, Ryan Cloutier, Stéphane Udry, Matías R. Díaz, Nuno C. Santos, C. Lovis, Damien Ségransan, Robert L. Morris, Michael Vezie, Eric R. Morgan, M. Mayor, Kristen Menou, X. Delfosse, D. W. Latham, James S. Jenkins, P. Figueira, Jon M. Jenkins, Roland Vanderspek, François Bouchy, Peter Tenenbaum, T. Forveille, Nicola Astudillo-Defru, Felipe Murgas, J. Villasenor, Joshua N. Winn, Jose-Manuel Almenara, René Doyon, Xavier Bonfils, and Jeffrey C. Smith
Subjects: Physics, Super-Earth, Outer planets, 010504 meteorology & atmospheric sciences, Astronomy and Astrophysics, Astrophysics, Planetary system, 01 natural sciences, Radial velocity, Planetary science, 13. Climate action, Space and Planetary Science, Planet, Neptune, 0103 physical sciences, Terrestrial planet, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Aims.L 98-59 (TIC 307210830, TOI-175) is a nearby M3 dwarf around which TESS revealed three small transiting planets (0.80, 1.35, 1.57 Earth radii) in a compact configuration with orbital periods shorter than 7.5 days. Here we aim to measure the masses of the known transiting planets in this system using precise radial velocity (RV) measurements taken with the HARPS spectrograph.Methods.We considered both trained and untrained Gaussian process regression models of stellar activity, which are modeled simultaneously with the planetary signals. Our RV analysis was then supplemented with dynamical simulations to provide strong constraints on the planets’ orbital eccentricities by requiring long-term stability.Results.We measure the planet masses of the two outermost planets to be 2.42 ± 0.35 and 2.31 ± 0.46 Earth masses, which confirms the bulk terrestrial composition of the former and eludes to a significant radius fraction in an extended gaseous envelope for the latter. We are able to place an upper limit on the mass of the smallest, innermost planet of e< 0.1.Conclusions.L 98-59 is likely a compact system of two rocky planets plus a third outer planet with a lower bulk density possibly indicative of the planet having retained a modest atmosphere. The system offers a unique laboratory for studies of planet formation, dynamical stability, and comparative atmospheric planetology as the two outer planets are attractive targets for atmospheric characterization through transmission spectroscopy. Continued RV monitoring will help refine the characterization of the innermost planet and potentially reveal additional planets in the system at wider separations.
Published: 2019
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73 results on '"Nicola Astudillo-Defru"'

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