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Start Over Author "Forveille, T." Topic techniques: radial velocities
24 results on '"Forveille, T."'

1. 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

Kosiarek, Molly R, Crossfield, Ian JM, Hardegree-Ullman, Kevin K, Livingston, John H, Benneke, Björn, Henry, Gregory W, Howard, Ward S, Berardo, David, Blunt, Sarah, Fulton, Benjamin J, Hirsch, Lea A, Howard, Andrew W, Isaacson, Howard, Petigura, Erik A, Sinukoff, Evan, Weiss, Lauren, Bonfils, X, Dressing, Courtney D, Knutson, Heather A, Schlieder, Joshua E, Werner, Michael, Gorjian, Varoujan, Krick, Jessica, Morales, Farisa Y, Astudillo-Defru, Nicola, Almenara, J-M, Delfosse, X, Forveille, T, Lovis, C, Mayor, M, Murgas, F, Pepe, F, Santos, NC, Udry, S, Corbett, HT, Fors, Octavi, Law, Nicholas M, Ratzloff, Jeffrey K, and del Ser, Daniel

Subjects
planets and satellites: composition, techniques: photometric, techniques: radial velocities, astro-ph.EP, Astronomical and Space Sciences, 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, 2.14, and 12.58 M ⊕, respectively. K2-3 d was not significantly detected and has a 3σ upper limit of 2.80 M ⊕ . These two systems are training cases for future TESS systems; due to the low planet densities (ρ < 3.7 g cm -3 ) 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

2. A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b⋆⋆⋆

Author

Lanotte, AA, Gillon, M, Demory, B-O, Fortney, JJ, Astudillo, N, Bonfils, X, Magain, P, Delfosse, X, Forveille, T, Lovis, C, Mayor, M, Neves, V, Pepe, F, Queloz, D, Santos, N, and Udry, S

Subjects
techniques: photometric, techniques: radial velocities, planetary systems, infrared: general, stars: individual: GJ436, astro-ph.EP, Astronomical and Space Sciences, Astronomy & Astrophysics
Abstract

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects.

Published
2014

3. TOI-663: A newly discovered multi-planet system with three transiting mini-Neptunes orbiting an early M star.

Author

Cointepas, M., Bouchy, F., Almenara, J. M., Bonfils, X., Astudillo-Defru, N., Knierim, H., Stalport, M., Mignon, L., Grieves, N., Bean, J., Brady, M., Burt, J., Canto Martins, B. L., Collins, K. A., Collins, K. I., Delfosse, X., de Medeiros, J. R., Demory, B.-O., Dorn, C., and Forveille, T.

Subjects
ORBITS (Astronomy), STELLAR orbits, GAUSSIAN processes, PLANETS, INTEGRATED software, EXTRASOLAR planets
Abstract

We present the detection of three exoplanets orbiting the early M dwarf TOI-663 (TIC 54962195; V = 13.7 mag, J = 10.4 mag, R★ = 0.512 ± 0.015 R⊙, M★ = 0.514 ± 0.012 M⊙, d = 64 pc). TOI-663 b, c, and d, with respective radii of 2.27 ± 0.10 R⊕, 2.26 ± 0.10 R⊕, and 1.92 ± 0.13 R⊕ and masses of 4.45 ± 0.65 M⊕, 3.65 ± 0.97 M⊕, and <5.2 M⊕ at 99%, are located just above the radius valley that separates rocky and volatile-rich exoplanets. The planet candidates are identified in two TESS sectors and are validated with ground-based photometric follow-up, precise radial-velocity measurements, and high-resolution imaging. We used the software package juliet to jointly model the photometric and radial-velocity datasets, with Gaussian processes applied to correct for systematics. The three planets discovered in the TOI-663 system are low-mass mini-Neptunes with radii significantly larger than those of rocky analogs, implying that volatiles, such as water, must predominate. In addition to this internal structure analysis, we also performed a dynamical analysis that confirmed the stability of the system. The three exoplanets in the TOI-663 system, similarly to other sub-Neptunes orbiting M dwarfs, have been found to have lower densities than planets of similar sizes orbiting stars of different spectral types. [ABSTRACT FROM AUTHOR]

Published
2024
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4. XIII. Two planets around M-dwarfs Gl617A and Gl96

Author

Hobson, M. J., Díaz, R. F., Delfosse, X., Astudillo-Defru, N., Boisse, I., Bouchy, F., Bonfils, X., Forveille, T., Hara, N., Arnold, L., Borgniet, S., Bourrier, V., Brugger, B., Cabrera, N., Courcol, B., Dalal, S., Deleuil, M., Demangeon, O., Dumusque, X., Ehrenreich, D., Hébrard, G., Kiefer, F., Lopez, T., Mignon, L., Montagnier, G., Mousis, O., Moutou, C., Pepe, F., Rey, J., Santerne, A., Santos, N., Stalport, M., Ségransan, D., Udry, S., Wilson, P. A., 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 Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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 Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), 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), 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), 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), 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 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), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11), Université de Genève = University of Geneva (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), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto = University of Porto, University of Warwick [Coventry], 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], Universidade do Porto [Porto], Université Pierre et Marie Curie - Paris 6 (UPMC)-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-Centre National de la Recherche Scientifique (CNRS), 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 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), and Universidade do Porto

Subjects
[SDU]Sciences of the Universe [physics], stars: late-type, techniques: radial velocities, stars: individual: Gl617A, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], planetary systems, stars: individual: Gl96
Abstract

International audience; Aims. 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.Methods. The radial velocity data, ancillary spectroscopic indices, and ground-based photometric measurements were analyzed with classical and ℓ1 periodograms. The stellar activity was modeled as a correlated Gaussian noise and its impact on the planet detection was measured with a new technique.Results. The SOPHIE data support the detection of five planets, each with m sin i ≈ 6 M⊕, 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 ≈1.2 R⊕. A compatible signal is seen in the radial velocities, which confirms the detection of an additional planet and yields a ≈2 M⊕ mass estimate.Conclusions. 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.

Published
2020
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5. Seven new brown dwarfs and constraints on the brown dwarf desert

Author

Kiefer, F., Hébrard, G., Sahlmann, J., Sousa, S. G., Forveille, T., Santos, N., Mayor, M., Deleuil, M., Wilson, P. A., Dalal, S., Díaz, R. F., Henry, G. W., Hagelberg, J., Hobson, M. J., Demangeon, O., Bourrier, V., Delfosse, X., Arnold, L., Astudillo-Defru, N., Beuzit, J.-L., Boisse, I., Bonfils, X., Borgniet, S., Bouchy, F., Courcol, B., Ehrenreich, D., Hara, N., Lagrange, A.-M., Lovis, C., Montagnier, G., Moutou, C., Pepe, F., Perrier, C., Rey, J., Santerne, A., Ségransan, D., Udry, S., Vidal-Madjar, A., 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), 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 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]), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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), 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 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 de Paris (UP), Universidade do Porto = University of Porto, Université de Genève = University of Geneva (UNIGE), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), 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), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Universidade de Sao Paulo, Instituto Ocenografico, 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), Universidade do Porto [Porto], University of Warwick [Coventry], Center of Excellence in Information Systems, Université Paris-Sud - Paris 11 (UP11), 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], Tri ionique par les Systèmes Moléculaires auto-assemblés (LTSM), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Université de Montpellier (UM), 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)-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)

Subjects
[PHYS]Physics [physics], observational -methods, numerical, [SDU]Sciences of the Universe [physics], radial velocities -methods, techniques: radial velocities, brown dwarfs -binaries, methods: observational, spectroscopic -techniques, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], binaries: spectroscopic, methods: numerical, brown dwarfs
Abstract

International audience; 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%. RV data are only available at the CDS and Tables B.1, B.3-B.7 are also available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/cat/J/A+A/631/A125

Published
2019
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6. Characterization of the L 98-59 multi-planetary system with HARPS

Author

Cloutier, R., Astudillo-Defru, N., Bonfils, X., Berdiñas, Z., Ricker, G., Vanderspek, R., Latham, D. W., Seager, S., Winn, J., Jenkins, J. S., Almenara, J. M., Bouchy, F., Delfosse, X., Díaz, M. R., Díaz, R. F., Doyon, R., Figueira, P., Forveille, T., Kurtovic, N. T., Lovis, C., Mayor, M., Menou, K., Morgan, E., Morris, R., Muirhead, P., Murgas, F., Pepe, F., Santos, N. C., Ségransan, D., Smith, J. C., Tenenbaum, P., Torres, G., Udry, S., Vezie, M., Villasenor, J., Université du Québec à Rimouski (UQAR), Universidad de Concepción [Chile], 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), Center for Space Research [Cambridge] (CSR), Massachusetts Institute of Technology (MIT), Universidad de Chile, 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), Université de Montréal (UdeM), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto [Porto], Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Boston University [Boston] (BU), Stanford Linear Accelerator Center (SLAC), Stanford University [Stanford], 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), Universidade do Porto, SLAC National Accelerator Laboratory (SLAC), and Stanford University

Subjects
planets and satellites: terrestrial planets, stars: low-mass, [SDU]Sciences of the Universe [physics], techniques: radial velocities, Astrophysics::Earth and Planetary Astrophysics, planetary systems, stars: individual: L 98-59
Abstract

International audience; 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

Published
2019
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7. XIV. A temperate ( T eq ~ 300 K) super-earth around the nearby star Gliese 411

Author

Díaz, R., Delfosse, X., Hobson, M., Boisse, I., Astudillo-Defru, N., Bonfils, Xavier, Henry, G., Arnold, L., Bouchy, F., Bourrier, V., Brugger, B., Dalal, S., Deleuil, M., Demangeon, O., Dolon, F., Dumusque, X., Forveille, T., Hara, N., Hébrard, G., Kiefer, F., Lopez, Téodolina, Mignon, L., Moreau, F., Mousis, O., Moutou, C., Pepe, F., Perruchot, S., Richaud, Y., Santerne, A., Santos, N., Sottile, R., Stalport, M., Ségransan, D., Udry, S., Unger, N., Wilson, P., 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), 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), Universidad de Concepción [Chile], Center of Excellence in Information Systems, 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 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), 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), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (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), Observatoire de Haute-Provence (OHP), 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), Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto [Porto], University of Warwick [Coventry], 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]), 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), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), 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), Universidade do Porto, Tennessee State University, Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire Optimisation de la Conception et Ingénierie de l'Environnement (LOCIE), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), 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), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Université de Genève = University of Geneva (UNIGE), Universidad de Concepción - University of Concepcion [Chile], and Universidade do Porto = University of Porto

Subjects
Gl 411, stars: individual: Gl 411, stars: low-mass, [SDU]Sciences of the Universe [physics], techniques: radial velocities, individual, radial velocities -stars, planetary systems -techniques, low-mass -stars, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], planetary systems
Abstract

International audience; Periodic radial velocity variations in the nearby M-dwarf star Gl 411 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-1, 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 Gl 411 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 256 and 350 K, and makes it too hot to be in the habitable zone. At a distance of only 2.5 pc, Gl 411 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. Full Table 2 is only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/625/A17Based on observations collected with the SOPHIE spectrograph on the 1.93-m telescope at Observatoire de Haute-Provence (CNRS), France by the SOPHIE Consortium.

Published
2019
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8. 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

Kosiarek, Molly R., Crossfield, Ian J. M., Hardegree-Ullman, Kevin K., Livingston, John H., Benneke, Björn, Henry, Gregory W., Howard, Ward S., Berardo, David, Blunt, Sarah, Fulton, Benjamin J., Hirsch, Lea A., Howard, Andrew W., Isaacson, Howard, Petigura, Erik A., Sinukoff, Evan, Weiss, Lauren, Bonfils, X., Dressing, Courtney D., Knutson, Heather A., Schlieder, Joshua E., Werner, Michael, Gorjian, Varoujan, Krick, Jessica, Morales, Farisa Y., Astudillo-Defru, Nicola, Almenara, J.-M., Delfosse, X., Forveille, T., Lovis, C., Mayor, M., Murgas, F., Pepe, F., Santos, N. C., Udry, S., Corbett, H. T., Fors, Octavi, Law, Nicholas M., Ratzloff, Jeffrey K., del Ser, Daniel, Kosiarek, Molly, Crossfield, Ian, Hardegree-Ullman, Kevin, Livingston, John, Henry, Gregory, Howard, Ward, Fulton, Benjamin, Hirsch, Lea, Howard, Andrew, Petigura, Erik, Dressing, Courtney, Knutson, Heather, Schlieder, Joshua, Morales, Farisa, Law, Nicholas, Ratzloff, Jeffrey, Ser, Daniel del, Département de Physique [Montréal], Université de Montréal [Montréal], Department of Earth and Planetary Science [UC Berkeley] (EPS), University of California [Berkeley], University of California-University of California, Institute for Astronomy [Honolulu], University of Hawai‘i [Mānoa] (UHM), Université de Montréal - UdeM (CANADA), Université de Montréal (UdeM), 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), Division of Geological and Planetary Sciences [Pasadena], California Institute of Technology (CALTECH), Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), Universidad de Concepción [Chile], Centro de Astrofísica da Universidade do Porto (CAUP), Universidade do Porto [Porto], Department of Astronomy and Astrophysics [UCSC Santa Cruz], University of California [Santa Cruz] (UCSC), MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology (MIT), SRI International [Menlo Park] (SRI), Infrared Processing and Analysis Center (IPAC), Caltech Department of Astronomy [Pasadena], Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, University of Leeds, Tennessee State University, 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 Universidade do Porto

Subjects
010504 meteorology & atmospheric sciences, FOS: Physical sciences, Astrophysics, Rotation, Ephemeris, 01 natural sciences, techniques: photometric, Planet, 0103 physical sciences, techniques: radial velocities, Transit (astronomy), 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Stellar rotation, planets and satellites: composition, Astronomy and Astrophysics, Radial velocity, Stars, Photometry (astronomy), 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Astrophysics - Earth and Planetary 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 are 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$^{+1.08}_{-1.04}$, and 12.58$^{+1.31}_{-1.28}$ M$_\oplus$ respectively. K2-3 d was not significantly detected and has a 3-$\sigma$ upper limit of 2.80 M$_\oplus$. These two systems are training cases for future TESS systems; due to the low planet densities ($\rho$ $, Comment: 21 pages, 11 figures, accepted to AJ

Published
2019
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9. Radial velocity follow-up of GJ1132 with HARPS

Author

Bonfils, X., Almenara, J.-M., Cloutier, R., Wünsche, A., Astudillo-Defru, N., Berta-Thompson, Z., Bouchy, F., Charbonneau, D., Delfosse, X., Díaz, R. F., Dittmann, J., Doyon, R., Forveille, T., Irwin, J., Lovis, C., Mayor, M., Menou, K., Murgas, F., Newton, E., Pepe, F., Santos, N. C., Udry, S., 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), Université du Québec à Rimouski (UQAR), Universidad de Concepción [Chile], 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), Université de Montréal (UdeM), Université du Texas, Observatoire Astronomique de l'Université de Genève (ObsGE), Université de Genève (UNIGE), 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
[SDU]Sciences of the Universe [physics], techniques: radial velocities, stars: late-type, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], planetary systems
Abstract

International audience; The source GJ1132 is a nearby red dwarf known to host a transiting Earth-size planet. After its initial detection, we pursued an intense follow-up with the HARPS velocimeter. We now confirm the detection of GJ1132b with radial velocities alone. We refined its orbital parameters, and in particular, its mass (mb = 1.66 ± 0.23 M⊕), density (ρb = 6.3 ± 1.3 g cm-3), and eccentricity (eb < 0.22; 95%). We also detected at least one more planet in the system. GJ1132c is a super-Earth with period Pc = 8.93 ± 0.01 days and minimum mass mc sinic = 2.64 ± 0.44 M⊕. Receiving about 1.9 times more flux than Earth in our solar system, its equilibrium temperature is that of a temperate planet (Teq = 230-300 K for albedos A = 0.75 - 0.00), which places GJ1132c near the inner edge of the so-called habitable zone. Despite an a priori favorable orientation for the system, Spitzer observations reject most transit configurations, leaving a posterior probability

Published
2018
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10. Spin-orbit alignment and magnetic activity in the young planetary system AU Mic.

Author

Martioli, E., Hébrard, G., Moutou, C., Donati, J.-F., Artigau, É., Cale, B., Cook, N. J., Dalal, S., Delfosse, X., Forveille, T., Gaidos, E., Plavchan, P., Berberian, J., Carmona, A., Cloutier, R., Doyon, R., Fouqué, P., Klein, B., Lecavelier des Etangs, A., and Manset, N.

Subjects
PLANETARY systems, PROTOPLANETARY disks, STELLAR activity, STELLAR rotation, STELLAR magnetic fields, MAGNETIC fields
Abstract

We present high-resolution near-infrared spectropolarimetric observations using the SPIRou instrument at Canada-France-Hawaii Telescope (CFHT) during a transit of the recently detected young planet AU Mic b, with supporting spectroscopic data from iSHELL at NASA InfraRed Telescope Facility. We detect Zeeman signatures in the Stokes V profiles and measure a mean longitudinal magnetic field of ¯Bℓ = 46.3 ± 0.7 B ¯ ℓ = 46.3 ± 0.7 $ \overline{B}_\ell=46.3\pm0.7 $ G. Rotationally modulated magnetic spots likely cause long-term variations of the field with a slope of dBℓ/dt = −108.7 ± 7.7 G d−1. We apply the cross-correlation technique to measure line profiles and obtain radial velocities through CCF template matching. We find an empirical linear relationship between radial velocity and Bℓ, which allows us to estimate the radial-velocity induced by stellar activity through rotational modulation of spots for the five hours of continuous monitoring of AU Mic with SPIRou. We model the corrected radial velocities for the classical Rossiter-McLaughlin effect, using MCMC to sample the posterior distribution of the model parameters. This analysis shows that the orbit of AU Mic b is prograde and aligned with the stellar rotation axis with a sky-projected spin-orbit obliquity of λ = 0°−15°+18° λ = 0 ° − 15 ° + 18 ° $ {\lambda=0^{\circ}}^{+18^{\circ}}_{-15^{\circ}} $. The aligned orbit of AU Mic b indicates that it formed in the protoplanetary disk that evolved into the current debris disk around AU Mic. [ABSTRACT FROM AUTHOR]

Published
2020
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11. Spectral and atmospheric characterisation of a new benchmark brown dwarf HD 13724 B.

Author

Rickman, E. L., Ségransan, D., Hagelberg, J., Beuzit, J.-L., Cheetham, A., Delisle, J.-B., Forveille, T., and Udry, S.

Subjects
BROWN dwarf stars, VERY large telescopes, EXTRASOLAR planets, STELLAR atmospheres, ANGULAR distance, AGE of stars, DWARF stars
Abstract

Context. HD 13724 is a nearby solar-type star at 43.48 ± 0.06 pc hosting a long-period low-mass brown dwarf detected with the CORALIE echelle spectrograph as part of the historical CORALIE radial-velocity search for extra-solar planets. The companion has a minimum mass of 26:77+4:4 -2:2 MJup and an expected semi-major axis of ~240 mas making it a suitable target for further characterisation with high-contrast imaging, in particular to measure its inclination, mass, and spectrum and thus establish its substellar nature. Aims. Using high-contrast imaging with the SPHERE instrument on the Very Large Telescope (VLT), we are able to directly image a brown dwarf companion to HD 13724 and obtain a low-resolution spectrum. Methods. We combine the radial-velocity measurements of CORALIE and HARPS taken over two decades and high-contrast imaging from SPHERE to obtain a dynamical mass estimate. From the SPHERE data we obtain a low-resolution spectrum of the companion from Y to J band, as well as photometric measurements from IRDIS in the J, H; and K bands. Results. Using high-contrast imaging with the SPHERE instrument at the VLT, we report the first images of a brown dwarf companion orbiting the host star HD 13724. It has an angular separation of 175.6 ± 4.5 mas and an H-band contrast of 10:61 ± 0:16 mag, and using the age estimate of the star to be ~1 Gyr gives an isochronal mass estimate of ~44 MJup. By combining radial-velocity and imaging data we also obtain a dynamical mass of 50:5+3:3 -3:5 MJup. Through fitting an atmospheric model, we estimate a surface gravity of log g = 5:5 and an effective temperature of 1000 K. A comparison of its spectrum with observed T dwarfs estimates a spectral type of T4 or T4.5, with a T4 object providing the best fit. [ABSTRACT FROM AUTHOR]

Published
2020
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12. Confirmation of the radial velocity super-Earth K2-18c with HARPS and CARMENES.

Author

Cloutier, R., Astudillo-Defru, N., Doyon, R., Bonfils, X., Almenara, J.-M., Bouchy, F., Delfosse, X., Forveille, T., Lovis, C., Mayor, M., Menou, K., Murgas, F., Pepe, F., Santos, N. C., Udry, S., and Wünsche, A.

Subjects
RADIAL velocity of stars, STELLAR activity, TIME series analysis, WAVELENGTHS, SAMPLING (Process)
Abstract

In an earlier campaign to characterize the mass of the transiting temperate super-Earth K2-18b with HARPS, a second, non-transiting planet was posited to exist in the system at ~9 days. Further radial velocity follow-up with the CARMENES spectrograph visible channel revealed a much weaker signal at 9 days, which also appeared to vary chromatically and temporally, leading to the conclusion that the origin of the 9-day signal was more likely related to stellar activity than to a planetary presence. Here we conduct a detailed reanalysis of all available RV time-series – including a set of 31 previously unpublished HARPS measurements – to investigate the effects of time-sampling and of simultaneous modelling of planetary plus activity signals on the existence and origin of the curious 9-day signal. We conclude that the 9-day signal is real and was initially seen to be suppressed in the CARMENES data due to a small number of anomalous measurements, although the exact cause of these anomalies remains unknown. Investigation of the signal's evolution in time with wavelength and detailed model comparison reveals that the 9-day signal is most likely planetary in nature. Using this analysis, we reconcile the conflicting HARPS and CARMENES results and measure precise and self-consistent planet masses of mp,b = 8.63 ± 1.35 and mp,c sinic = 5.62 ± 0.84 Earth masses. This work, along with the previously published RV papers on the K2-18 planetary system, highlights the importance of understanding the time-sampling and of modelling the simultaneous planet plus stochastic activity, particularly when searching for sub-Neptune-sized planets with radial velocities. [ABSTRACT FROM AUTHOR]

Published
2019
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13. Extrasolar planets and brown dwarfs around AF-type stars: X. The SOPHIE sample: combining the SOPHIE and HARPS surveys to compute the close giant planet mass-period distribution around AF-type stars.

Author

Borgniet, S., Lagrange, A.-M., Meunier, N., Galland, F., Arnold, L., Astudillo-Defru, N., Beuzit, J.-L., Boisse, I., Bonfils, X., Bouchy, F., Debondt, K., Deleuil, M., Delfosse, X., Desort, M., Díaz, R. F., Eggenberger, A., Ehrenreich, D., Forveille, T., Hébrard, G., and Loeillet, B.

Subjects
BROWN dwarf stars, EXTRASOLAR planets, RADIAL velocity of galaxies, BINARY stars, STELLAR mass
Abstract

Context. The impact of stellar mass on the properties of giant planets is still not fully understood. Main-sequence (MS) stars more massive than the Sun remain relatively unexplored in radial velocity (RV) surveys, due to their characteristics which hinder classical RV measurements. Aims. Our aim is to characterize the close (up to ~2 au) giant planet (GP) and brown dwarf (BD) population around AF MS stars and compare this population to stars with different masses. Methods. We used the SOPHIE spectrograph located on the 1.93 m 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 substellar companions and computed the GP and BD occurrence rates combining the present SOPHIE survey and a similar HARPS survey. Results. We present new data on two known planetary systems around the F5-6V dwarfs HD 16232 and HD 113337. 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 15 binaries or massive substellar companions with high-amplitude RV variations or long-term RV trends. Based on 225 targets observed with SOPHIE and/or HARPS, we constrain the BD frequency within 2–3 au around AF stars to be below 4% (1σ). For Jupiter-mass GPs within 2–3 au (periods ≤103 days), we find the occurrence rate to be 3.7−1+3 $3.7_{-1}^{+3}$ 3.7 − 1 + 3 % around AF stars with masses <1.5 M⊙, and to be ≤6% (1σ) around AF stars with masses >1.5 M⊙. For periods shorter than 10 days, we find the GP occurrence rate to be below 3 and 4.5% (1σ), respectively. Our results are compatible with the GP frequency reported around FGK dwarfs and are compatible with a possible increase in GP orbital periods with stellar mass as predicted by formation models. [ABSTRACT FROM AUTHOR]

Published
2019
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14. A temperate exo-Earth around a quiet M dwarf at 3.4 parsec.

Author

Bonfils, X., Astudillo-Defru, N., Díaz, R., Almenara, J.-M., Forveille, T., Bouchy, F., Delfosse, X., Lovis, C., Mayor, M., Murgas, F., Pepe, F., C. Santos, N., Ségransan, D., Udry, S., and Wünsche, A.

Subjects
DWARF stars, EARTH (Planet), PARSEC, TEMPERATE climate, LARGE astronomical telescopes
Abstract

The combination of high-contrast imaging and high-dispersion spectroscopy, which has successfully been use 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 O2 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 ~5 parsec. 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 msin i = 1:35 M⊕ and an orbital period of 9.9 days. Ross 128 b receives less than 1.5 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 (>3λ=D) in the optical bands of O2. [ABSTRACT FROM AUTHOR]

Published
2018
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15. The HARPS search for southern extra-solar planets: XLII. A system of Earth-mass planets around the nearby M dwarf YZ Ceti.

Author

Astudillo-Defru, N., Díaz, R. F., Bonfils, X., Almenara, J. M., Delisle, J.-B., Bouchy, F., Delfosse, X., Forveille, T., Lovis, C., Mayor, M., Murgas, F., Pepe, F., Santos, N. C., Ségransan, D., Udry, S., and Wünsche, A.

Subjects
EXTRASOLAR planets, DWARF stars, LOW mass stars, PLANETARY orbits, RADIAL velocity of stars
Abstract

Exoplanet surveys have shown that systems with multiple low-mass planets on compact orbits are common. Except for a 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 this context, we monitored the low-mass (0.13 M⊙) M dwarf YZ Cet (GJ 54.1, HIP 5643) intensively and obtained radial velocities and stellar-activity indicators derived from spectroscopy and photometry, respectively. We find strong evidence that it is orbited by at least three planets in compact orbits (POrb = 1.97, 3.06, 4.66 days), with the inner two near a 2:3 mean-motion resonance. The minimum masses are comparable to the mass of Earth (M sin i = 0.75 ± 0.13, 0.98 ± 0.14, and 1.14 ± 0.17 M⊕), and they are also the lowest masses measured by radial velocity so far. We note the possibility for a fourth planet with an even lower mass of M sin i = 0.472 ± 0.096 M⊕ at POrb = 1.04 days. An n-body dynamical model is used to place further constraints on the system parameters. At 3.6 parsecs, YZ Cet is the nearest multi-planet system detected to date. [ABSTRACT FROM AUTHOR]

Published
2017
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16. 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

Astudillo-Defru, N., Forveille, T., Bonfils, X., Ségransan, D., Bouchy, F., Delfosse, X., Lovis, C., Mayor, M., Murgas, F., Pepe, F., Santos, N. C., Udry, S., and Wünsche, A.

Subjects
*EXTRASOLAR planets, *STELLAR activity, *PLANETS, *ALPHA Centauri, *HABITABLE planets, *ORIGIN of planets
Abstract

Context. Low-mass stars are currently the best targets when searching for rocky planets in the habitable zone of their host star. Over the last 13 yr, precise radial velocities measured with the HARPS spectrograph have identified over a dozen super-Earths and Earth-mass planets (msin i ≤ 10 M⊙) around M dwarfs, with a well-understood selection function. This well-defined sample provides information on their frequency of occurrence and on the distribution of their orbital parameters, and therefore already constrains our understanding of planetary formation. The subset of these low-mass planets that were found within the habitable zone of their host star also provide prized targets for future searches of atmospheric biomarkers. Aims. We are working to extend this planetary sample to lower masses and longer periods through dense and long-term monitoring of the radial velocity of a small M dwarf sample. Methods. We obtained large numbers of HARPS spectra for the M dwarfs GJ 3138, GJ 3323, GJ 273, GJ 628, and GJ 3293, from which we derived radial velocities (RVs) and spectroscopic activity indicators. We searched for variabilities, periodicities, Keplerian modulations, and correlations, and attribute the radial-velocity variations to combinations of planetary companions and stellar activity. Results. We detect 12 planets, 9 of which are new with masses ranging from 1.17 to 10.5 M⊙. These planets have relatively short orbital periods (P < 40 d), except for two that have periods of 217.6 and 257.8 days. Among these systems, GJ 273 harbor two planets with masses close to the Earth's. With a distance of only 3.8 parsec, GJ 273 is the second nearest known planetary system - after Proxima Centauri - with a planet orbiting the circumstellar habitable zone. [ABSTRACT FROM AUTHOR]

Published
2017
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17. The SOPHIE search for northern extrasolar planets: XII. Three giant planets suitable for astrometric mass determination with Gaia.

Author

Rey, J., Hébrard, G., Bouchy, F., Bourrier, V., Boisse, I., Santos, N. C., Arnold, L., Astudillo-Defru, N., Bonfils, X., Borgniet, S., Courcol, B., Deleuil, M., Delfosse, X., Demangeon, O., Díaz, R. F., Ehrenreich, D., Forveille, T., Marmier, M., Moutou, C., and Pepe, F.

Subjects
EXTRASOLAR planets, ASTROMETRY, RADIAL velocity of stars, SPECTROGRAPHS
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 yr. All three stars, HD 17674, HD 42012 and HD 29021 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. [ABSTRACT FROM AUTHOR]

Published
2017
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18. The HARPS search for southern extra-solar planets XXXVI. Planetary systems and stellar activity of the M dwarfs GJ 3293, GJ 3341, and GJ 3543.

Author

Astudillo-Defru, N., Bonfils, X., Delfosse, X., Ségransan, D., Forveille, T., Bouchy, F., Gillon, M., Lovis, C., Mayor, M., Neves, V., Pepe, F., Perrier, C., Queloz, D., Rojo, P., Santos, N. C., and Udry, S.

Subjects
PLANETS, STELLAR activity, LOW mass stars, ASTRONOMICAL observations, ARTIFICIAL satellites in astronomy
Abstract

Context. Planetary companions of a fixed mass induce reflex motions with a larger amplitude around lower-mass stars, which adds to making M dwarfs excellent targets for extra-solar planet searches. The most recent velocimeters with a stability of ~1 ms-1 can detect very low-mass planets out to the habitable zone of these stars. Low-mass small planets are abundant around M dwarfs, and most of the known potentially habitable planets orbit one of these cool stars. Aims. Our M-dwarf radial velocity monitoring with HARPS on the ESO 3.6 m telescope at La Silla observatory makes a major contribution to this sample. Methods. We present here dense radial velocity (RV) time series for three M dwarfs observed over ~five years: GJ 3293 (0.42 M⊕), GJ 3341 (0.47 M⊕), and GJ 3543 (0.45 M⊕). We extracted these RVs through minimum χ2-matching of each spectrum against a stack of all observed spectra for the same star that has a high signal-to-noise ratio. We then compared potential orbital signals against several stellar activity indicators to distinguish the Keplerian variations induced by planets from the spurious signals that result from rotational modulation of stellar surface inhomogeneities and from activity cycles. Results. Two Neptune-mass planets - m sin(i) = 1:4 ± 0:1 and 1:3 ± 0:1Mnept - orbit GJ 3293 with periods P = 30:60 ± 0:02 d and P = 123:98 ± 0:38 d, possibly together with a super-Earth - m sin(i) ~ 7:9 ± 1:4 M⊕ - with period P = 48:14 ± 0:12 d. A super-Earth - m sin(i) ~ 6:1 M⊕ - orbits GJ 3341 with P = 14:207 ± 0:007 d. The RV variations of GJ 3543, on the other hand, reflect its stellar activity rather than planetary signals. [ABSTRACT FROM AUTHOR]

Published
2015
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19. A global analysis of Spitzer and new HARPS data confirms the loneliness and metal-richness of GJ 436 b.

Author

Lanotte, A. A., Gillon, M., Demory, B.-O., Fortney, J. J., Astudillo, N., Bonfils, X., Magain, P., Delfosse, X., Forveille, T., Lovis, C., Mayor, M., Neves, V., Pepe, F., Queloz, D., Santos, N., and Udry, S.

Subjects
RADIAL velocity of stars, STARS, PLANETARY research, ASTRONOMICAL research, ASTROPHYSICS research
Abstract

Context. GJ 436b is one of the few transiting warm Neptunes for which a detailed characterisation of the atmosphere is possible, whereas its non-negligible orbital eccentricity calls for further investigation. Independent analyses of several individual datasets obtained with Spitzer have led to contradicting results attributed to the different techniques used to treat the instrumental effects. Aims. We aim at investigating these previous controversial results and developing our knowledge of the system based on the full Spitzer photometry dataset combined with new Doppler measurements obtained with the HARPS spectrograph. We also want to search for additional planets. Methods. We optimise aperture photometry techniques and the photometric deconvolution algorithm DECPHOT to improve the data reduction of the Spitzer photometry spanning wavelengths from 3-24 μm. Adding the high-precision HARPS radial velocity data, we undertake a Bayesian global analysis of the system considering both instrumental and stellar e ects on the flux variation. Results. We present a refined radius estimate of RP = 4:10 ± 0:16 R☉, mass MP = 25:4 ± 2:1 M☉, and eccentricity e = 0:162 ± 0:004 for GJ 436b. Our measured transit depths remain constant in time and wavelength, in disagreement with the results of previous studies. In addition, we find that the post-occultation flare-like structure at 3.6 μm that led to divergent results on the occultation depth measurement is spurious. We obtain occultation depths at 3.6, 5.8, and 8.0 μm that are shallower than in previous works, in particular at 3.6 μm. However, these depths still appear consistent with a metal-rich atmosphere depleted in methane and enhanced in CO/CO2, although perhaps less than previously thought. We could not detect a significant orbital modulation in the 8 μm phase curve. We find no evidence of a potential planetary companion, stellar activity, or a stellar spin-orbit misalignment. Conclusions. Recent theoretical models invoking high-metallicity atmospheres for warm Neptunes are a reasonable match to our results, but we encourage new modelling efforts based on our revised data. Future observations covering a wide wavelength range of GJ 436b and other Neptune-class exoplanets will further illuminate their atmosphere properties, whilst future accurate radial velocity measurements might explain the eccentricity. [ABSTRACT FROM AUTHOR]

Published
2014
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20. The SOPHIE search for northern extrasolar planets VI. Three new hot Jupiters in multi-planet extrasolar systems.

Author

Moutou, C., Hébrard, G., Bouchy, F., Arnold, L., Santos, N. C., Astudillo-Defru, N., Boisse, I., Bonfils, X., Borgniet, S., Delfosse, X., Díaz, R. F., Ehrenreich, D., Forveille, T., Gregorio, J., Labrevoir, O., Lagrange, A. M., Montagnier, G., Montalto, M., Pepe, F., and Sahlmann, J.

Subjects
HOT Jupiters, EXTRASOLAR planets, RADIAL velocity of stars, PHOTOMETRIC stereo
Abstract

We present high-precision radial-velocity measurements of three solar-type stars: HD13908, HD159243, and HIP 91258. The observations were made with the SOPHIE spectrograph at the 1.93 m telescope of the Observatoire de Haute-Provence (France). They show that these three bright stars host exoplanetary systems composed of at least two companions. HD13908 b is a planet with a minimum mass of 0.865 ± 0.035 MJup on a circular orbit with a period of 19.382 ± 0.006 days. There is an outer massive companion in the system with a period of 931 ± 17 days, e = 0.12 ± 0.02, and a minimum mass of 5.13 ± 0.25 MJup. The star HD159243 also has two detected companions with respective masses, periods, and eccentricities of Mp= 1.13 ± 0.05 and 1.9 ± 0.13 MJup, P = 12.620 ± 0.004 and 248.4 ± 4.9 days, and e = 0.02 ± 0.02 and 0.075 ± 0.05. Finally, the star HIP 91258 has a planetary companion with a minimum mass of 1.068 ± 0.038 MJup, an orbital period of 5.0505 ± 0.0015 days, and a quadratic trend indicating an outer planetary or stellar companion that is as yet uncharacterized. The planet-hosting stars HD13908, HD159243, and HIP 91258 are main-sequence stars of spectral types F8V, G0V, and G5V, respectively, with moderate activity levels. HIP 91258 is slightly over-metallic, while the other two stars have solar-like metallicity. The three systems are discussed in the frame of formation and dynamical evolution models of systems composed of several giant planets. [ABSTRACT FROM AUTHOR]

Published
2014
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21. Extrasolar planets and brown dwarfs around A-F type stars.

Author

Borgniet, S., Boisse, I., Lagrange, A.-M., Bouchy, F., Arnold, L., Díaz, R. F., Galland, F., Delorme, P., Hébrard, G., Santerne, A., Ehrenreich, D., Ségransan, D., Bonfils, X., Delfosse, X., Santos, N. C., Forveille, T., Moutou, C., Udry, S., Eggenberger, A., and Pepe, F.

Subjects
EXTRASOLAR planets, BROWN dwarf stars, ASTRONOMICAL instruments, ASTRONOMICAL photography, QUADRATIC differentials
Abstract

Aims. In the context of the search for extrasolar planets and brown dwarfs around early-type main-sequence stars we present the detection of a giant planet around the young F-type star HD113337. We estimated the age of the system to be 150-50+100 Myr. Interestingly, an infrared excess attributed to a cold debris disk was previously detected around this star. Methods. We used the SOPHIE spectrograph on the 1.93m telescope at Observatoire de Haute-Provence to obtain ~300 spectra over six years. We used our tool dedicated to the spectra analysis of A and F stars to derive the radial velocity variations. Results. The data reveal a period of 324.0-3.3+1.7 days that we attribute to a giant planet with a minimum mass of 2.83 ± 0.24 MJup in an eccentric orbit with e = 0.46 ± 0.04. A long-term quadratic drift, which we assign to be probably of stellar origin, is superimposed on the Keplerian solution. [ABSTRACT FROM AUTHOR]

Published
2014
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22. The HARPS search for southern extra-solar planets.

Author

Bonfils, X., Lo Curto, G., Correia, A. C. M., Laskar, J., Udry, S., Delfosse, X., Forveille, T., Astudillo-Defru, N., Benz, W., Bouchy, F., Gillon, M., Hébrard, G., Lovis, C., Mayor, M., Moutou, C., Naef, D., Neves, V., Pepe, F., Perrier, C., and Queloz, D.

Subjects
EXTRASOLAR planets, VELOCIMETERS, STARS with planets, HABITABLE zone (Outer space), STELLAR activity, HABITABLE planets, EARTH (Planet)
Abstract

The meter-per-second precision achieved by today's velocimeters enables us to search for 1-10 M⊕ planets in the habitable zone of cool stars. This paper reports on the detection of three planets orbiting GJ 163 (HIP 19394), a M3 dwarf monitored by our ESO/HARPS search for planets. We made use of the HARPS spectrograph to collect 150 radial velocities of GJ 163 over a period of eight years. We searched the radial-velocity time series for coherent signals and found five distinct periodic variabilities. We investigated the stellar activity and called into question the planetary interpretation for two signals. Before more data can be acquired we concluded that at least three planets are orbiting GJ 163. They have orbital periods of Pb = 8:632 ± 0:002, Pc = 25:63 ± 0:03, and Pd = 604 ± 8 days and minimum masses m sin i = 10:6 ± 0:6, 6:8 ± 0:9, and 29 ± 3 M⊕, respectively. We hold our interpretations for the two additional signals with periods P(e) = 19:4 and P(f) = 108 days. The inner pair presents an orbital period ratio of 2:97, but a dynamical analysis of the system shows that it lays outside the 3:1 mean motion resonance. The planet GJ 163c, in particular, is a super-Earth with an equilibrium temperature of Teq = (302 ± 10)(1 - A)1/4 K and may lie in the so-called habitable zone for albedo values (A = 0:34-0:89) moderately higher than that of Earth (A⊕ = 0:2-0:3). [ABSTRACT FROM AUTHOR]

Published
2013
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23. Long-term magnetic activity of a sample of M-dwarf stars from the HARPS program II. Activity and radial velocity.

Author

Gomes da Silva, J., Santos, N. C., Bonfils, X., Delfosse, X., Forveille, T., Udry, S., Dumusque, X., and Lovis, C.

Subjects
DWARF stars, COSMIC magnetic fields, EXTRASOLAR planets, STARS, ASTRONOMY
Abstract

Owing to their low mass and luminosity, M dwarfs are ideal targets if one hopes to find low-mass planets similar to Earth using the radial velocity (RV) method. However, stellar magnetic cycles could add noise or even mimic the RV signal of a long-period companion. We extend our previous study of the correlation between activity cycles and long-term RV variations for K dwarfs to the lower-end of the main sequence. Our objective is to detect any correlations between long-term activity variations and the observed RV of a sample of M dwarfs. We use a sample of 27 M-dwarfs with a median observational timespan of 5.9 years. The cross-correlation function (CCF) with its parameters RV, bisector inverse slope (BIS), full width at half maximum (FWHM), and contrast are computed from the HARPS spectrum. The activity index is derived using the Na i D doublet. These parameters are compared with the activity level of the stars to search for correlations. We detect RV variations up to ∼5 ms-1 that we can attribute to activity cycle effects. However, only 36% of the stars with long-term activity variability appear to have had their RV affected by magnetic cycles, on the typical timescale of ∼6 years. Therefore, we suggest a careful analysis of activity data when searching for extrasolar planets using long-timespan RV data. [ABSTRACT FROM AUTHOR]

Published
2012
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24. The SOPHIE search for northern extrasolar planets: IV. Massive companions in the planet-brown dwarf boundary.

Author

Díaz, R. F., Santerne, A., Sahlmann, J., Hébrard, G., Eggenberger, A., Santos, N. C., Moutou, C., Arnold, L., Boisse, I., Bonfils, X., Bouchy, F., Delfosse, X., Desort, M., Ehrenreich, D., Forveille, T., Lagrange, A.-M., Lovis, C., Pepe, F., Perrier, C., and Queloz, D.

Subjects
EXTRASOLAR planets, BROWN dwarf stars, PLANETS, ASTRONOMICAL photography, ORBITS (Astronomy)
Abstract

Context. The mass domain where massive extrasolar planets and brown dwarfs lie is still poorly understood. Indeed, not even a clear dividing line between massive planets and brown dwarfs has been established yet. This is partly because these objects are very scarce in close orbits around solar-type stars, the so-called brown dwarf desert. Owing to this, it has proven difficult to set up a strong observational base with which to compare models and theories of formation and evolution. Aims. We search to increase the current sample of massive sub-stellar objects with precise orbital parameters, and to constrain the true mass of detected sub-stellar candidates. Methods. The initial identification of sub-stellar candidates was made using precise radial velocity measurements obtained with the SOPHIE spectrograph at the 1.93-m telescope of the Haute-Provence Observatory. Subsequent characterisation of these candidates, with the principal aim of identifying stellar companions in low-inclination orbits, was made by means of different spectroscopic diagnostics such as the measurement of the bisector velocity span and the study of the correlation mask effect. With this objective, we also employed astrometric data from the Hipparcos mission, and a novel method of simulating stellar cross-correlation functions. Results. Seven new objects with minimum masses between ∼10 MJup and ∼90 MJup are detected. Out of these, two are identified as low-mass stars in low-inclination orbits, and two others have masses below the theoretical deuterium-burning limit, and are therefore planetary candidates. The remaining three are brown dwarf candidates; the current upper limits for their the masses do not allow us to conclude on their nature. Additionally, we have improved the parameters of an already-known brown dwarf (HD 137510b), confirmed by astrometry. [ABSTRACT FROM AUTHOR]

Published
2012
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