Search

Your search keyword '"Latham DW"' showing total 84 results
Start Over Author "Latham DW"
84 results on '"Latham DW"'

1. A super-Earth and a sub-Neptune orbiting the bright, quiet M3 dwarf TOI-1266

Author

Demory, B-O, Pozuelos, FJ, Chew, Y Gómez Maqueo, Sabin, L, Petrucci, R, Schroffenegger, U, Grimm, SL, Sestovic, M, Gillon, M, McCormac, J, Barkaoui, K, Benz, W, Bieryla, A, Bouchy, F, Burdanov, A, Collins, KA, de Wit, J, Dressing, CD, Garcia, LJ, Giacalone, S, Guerra, P, Haldemann, J, Heng, K, Jehin, E, Jofré, E, Kane, SR, Lillo-Box, J, Maigné, V, Mordasini, C, Morris, BM, Niraula, P, Queloz, D, Rackham, BV, Savel, AB, Soubkiou, A, Srdoc, G, Stassun, KG, Triaud, AHMJ, Zambelli, R, Ricker, G, Latham, DW, Seager, S, Winn, JN, Jenkins, JM, Calvario-Velásquez, T, Herrera, JA Franco, Colorado, E, Zepeda, EO Cadena, Figueroa, L, Watson, AM, Lugo-Ibarra, EE, Carigi, L, Guisa, G, Herrera, J, Díaz, G Sierra, Suárez, JC, Barrado, D, Batalha, NM, Benkhaldoun, Z, Chontos, A, Dai, F, Essack, Z, Ghachoui, M, Huang, CX, Huber, D, Isaacson, H, Lissauer, JJ, Morales-Calderón, M, Robertson, P, Roy, A, Twicken, JD, Vanderburg, A, and Weiss, LM

Subjects
instrumentation: detectors, planets and satellites: detection, astro-ph.EP, Astronomical and Space Sciences, Astronomy & Astrophysics
Abstract

We report the discovery and characterisation of a super-Earth and a sub-Neptune transiting the bright (K = 8.8), quiet, and nearby (37 pc) M3V dwarf TOI-1266. We validate the planetary nature of TOI-1266 b and c using four sectors of TESS photometry and data from the newly-commissioned 1-m SAINT-EX telescope located in San Pedro Mártir (México). We also include additional ground-based follow-up photometry as well as high-resolution spectroscopy and high-angular imaging observations. The inner, larger planet has a radius of R = 2.37-0.12+0.16 R and an orbital period of 10.9 days. The outer, smaller planet has a radius of R = 1.56-0.13+0.15 R on an 18.8-day orbit. The data are found to be consistent with circular, co-planar and stable orbits that are weakly influenced by the 2:1 mean motion resonance. Our TTV analysis of the combined dataset enables model-independent constraints on the masses and eccentricities of the planets. We find planetary masses of Mp = 13.5-9.0+11.0 M (

Published
2020

2. Erratum: An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star (AJ (2019) 158 (165) DOI: 10.3847/1538-3881/ab3e2f)

Author

Mayo, AW, Rajpaul, VM, Buchhave, LA, Dressing, CD, Mortier, A, Zeng, L, Fortenbach, CD, Aigrain, S, Bonomo, AS, Cameron, AC, Charbonneau, D, Coffinet, A, Cosentino, R, Damasso, M, Dumusque, X, Fiorenzano, AFM, Haywood, RD, Latham, DW, López-Morales, M, Malavolta, L, Micela, G, Molinari, E, Pearce, L, Pepe, F, Phillips, D, Piotto, G, Poretti, E, Rice, K, Sozzetti, A, and Udry, S

Subjects
Astronomy & Astrophysics, Astronomical and Space Sciences
Abstract

The semimajor axis and planet insolation flux of Kepler-538b were incorrectly calculated in the published article. This error did not impact any other parameters or any other results in the paper. Table 2 has been included in full here with the corrected semimajor axis and planet insolation flux values. We thank Arbab I. Arbab and Charles D. Fortenbach for bringing this to our attention.(Table Presented).

Published
2020

3. The Kepler Follow-up Observation Program. II. Stellar Parameters from Medium- and High-resolution Spectroscopy

Author

Furlan, E, Ciardi, DR, Cochran, WD, Everett, ME, Latham, DW, Marcy, GW, Buchhave, LA, Endl, M, Isaacson, H, Petigura, EA, Gautier, TN, Huber, D, Bieryla, A, Borucki, WJ, Brugamyer, E, Caldwell, C, Cochran, A, Howard, AW, Howell, SB, Johnson, MC, MacQueen, PJ, Quinn, SN, Robertson, P, Mathur, S, and Batalha, NM

Subjects
planets and satellites: fundamental parameters, stars: fundamental parameters, surveys, techniques: spectroscopic, astro-ph.SR, astro-ph.EP, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural), Astronomy & Astrophysics
Abstract

We present results from spectroscopic follow-up observations of stars identified in the Kepler field and carried out by teams of the Kepler Follow-up Observation Program. Two samples of stars were observed over 6 yr (2009-2015): 614 standard stars (divided into "platinum" and "gold" categories) selected based on their asteroseismic detections and 2667 host stars of Kepler Objects of Interest (KOIs), most of them planet candidates. Four data analysis pipelines were used to derive stellar parameters for the observed stars. We compare the T eff, log(g), and [Fe/H] values derived for the same stars by different pipelines; from the average of the standard deviations of the differences in these parameter values, we derive error floors of ∼100 K, 0.2 dex, and 0.1 dex for T eff, log(g), and [Fe/H], respectively. Noticeable disagreements are seen mostly at the largest and smallest parameter values (e.g., in the giant star regime). Most of the log(g) values derived from spectra for the platinum stars agree on average within 0.025 dex (but with a spread of 0.1-0.2 dex) with the asteroseismic log(g) values. Compared to the Kepler Input Catalog (KIC), the spectroscopically derived stellar parameters agree within the uncertainties of the KIC but are more precise and thus an important contribution toward deriving more reliable planetary radii.

Published
2018

4. Low false positive rate of kepler candidates estimated from a combination of spitzer and follow-up observations

Author

Désert, JM, Charbonneau, D, Torres, G, Fressin, F, Ballard, S, Bryson, ST, Knutson, HA, Batalha, NM, Borucki, WJ, Brown, TM, Deming, D, Ford, EB, Fortney, JJ, Gilliland, RL, Latham, DW, and Seager, S

Subjects
binaries: eclipsing, eclipses, planetary systems, planets and satellites: detection, techniques: polarimetric, astro-ph.EP, Astronomy & Astrophysics, Astronomical and Space Sciences, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry, Atomic, Molecular, Nuclear, Particle and Plasma Physics, Physical Chemistry (incl. Structural)
Abstract

NASA's Kepler mission has provided several thousand transiting planet candidates during the 4 yr of its nominal mission, yet only a small subset of these candidates have been confirmed as true planets. Therefore, the most fundamental question about these candidates is the fraction of bona fide planets. Estimating the rate of false positives of the overall Kepler sample is necessary to derive the planet occurrence rate. We present the results from two large observational campaigns that were conducted with the Spitzer Space Telescope during the the Kepler mission. These observations are dedicated to estimating the false positive rate (FPR) among the Kepler candidates. We select a sub-sample of 51 candidates, spanning wide ranges in stellar, orbital, and planetary parameter space, and we observe their transits with Spitzer at 4.5 μm. We use these observations to measures the candidate's transit depths and infrared magnitudes. An authentic planet produces an achromatic transit depth (neglecting the modest effect of limb darkening). Conversely a bandpass-dependent depth alerts us to the potential presence of a blending star that could be the source of the observed eclipse: a false positive scenario. For most of the candidates (85%), the transit depths measured with Kepler are consistent with the transit depths measured with Spitzer as expected for planetary objects, while we find that the most discrepant measurements are due to the presence of unresolved stars that dilute the photometry. The Spitzer constraints on their own yield FPRs between 5% and depending on the Kepler Objects of Interest. By considering the population of the Kepler field stars, and by combining follow-up observations (imaging) when available, we find that the overall FPR of our sample is low. The measured upper limit on the FPR of our sample is 8.8% at a confidence level of 3σ. This observational result, which uses the achromatic property of planetary transit signals that is not investigated by the Kepler observations, provides an independent indication that Kepler's FPR is low.

Published
2015

5. TOI-3235 b: A Transiting Giant Planet around an M4 Dwarf Star

Author

Hobson, MJ, Jordán, A, Bryant, EM, Brahm, R, Bayliss, D, Hartman, JD, Bakos, GI, Henning, T, Almenara, JM, Barkaoui, K, Benkhaldoun, Z, Bonfils, X, Bouchy, F, Charbonneau, D, Cointepas, M, Collins, KA, Eastman, JD, Ghachoui, M, Gillon, M, Goeke, RF, Horne, K, Irwin, JM, Jehin, E, Jenkins, JM, Latham, DW, Moldovan, D, Murgas, F, Pozuelos, FJ, Ricker, GR, Schwarz, RP, Seager, S, Srdoc, G, Striegel, S, Timmermans, M, Vanderburg, A, Vanderspek, R, Winn, JN, Hobson, MJ [0000-0002-5945-7975], Jordán, A [0000-0002-5389-3944], Bryant, EM [0000-0001-7904-4441], Brahm, R [0000-0002-9158-7315], Bayliss, D [0000-0001-6023-1335], Hartman, JD [0000-0001-8732-6166], Bakos, GI [0000-0001-7204-6727], Henning, T [0000-0002-1493-300X], Almenara, JM [0000-0003-3208-9815], Barkaoui, K [0000-0003-1464-9276], Benkhaldoun, Z [0000-0001-6285-9847], Bonfils, X [0000-0001-9003-8894], Bouchy, F [0000-0002-7613-393X], Charbonneau, D [0000-0002-9003-484X], Collins, KA [0000-0001-6588-9574], Eastman, JD [0000-0003-3773-5142], Ghachoui, M [0000-0003-3986-0297], Gillon, M [0000-0003-1462-7739], Horne, K [0000-0003-1728-0304], Jehin, E [0000-0001-8923-488X], Jenkins, JM [0000-0002-4715-9460], Latham, DW [0000-0001-9911-7388], Murgas, F [0000-0001-9087-1245], Pozuelos, FJ [0000-0003-1572-7707], Ricker, GR [0000-0003-2058-6662], Schwarz, RP [0000-0001-8227-1020], Seager, S [0000-0002-6892-6948], Vanderburg, A [0000-0001-7246-5438], Vanderspek, R [0000-0001-6763-6562], Winn, JN [0000-0002-4265-047X], Apollo - University of Cambridge Repository, University of St Andrews. School of Physics and Astronomy, and University of St Andrews. St Andrews Centre for Exoplanet Science

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Space and Planetary Science, 5101 Astronomical Sciences, MCP, FOS: Physical sciences, Astronomy and Astrophysics, 3rd-DAS, 5109 Space Sciences, 51 Physical Sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery of TOI-3235 b, a short-period Jupiter orbiting an M-dwarf with a stellar mass close to the critical mass at which stars transition from partially to fully convective. TOI-3235 b was first identified as a candidate from TESS photometry, and confirmed with radial velocities from ESPRESSO, and ground-based photometry from HATSouth, MEarth-South, TRAPPIST-South, LCOGT, and ExTrA. We find that the planet has a mass of $\mathrm{0.665\pm0.025\,M_J}$ and a radius of $\mathrm{1.017\pm0.044\,R_J}$. It orbits close to its host star, with an orbital period of $\mathrm{2.5926\,d}$, but has an equilibrium temperature of $\mathrm{\approx 604 \, K}$, well below the expected threshold for radius inflation of hot Jupiters. The host star has a mass of $\mathrm{0.3939\pm0.0030\,M_\odot}$, a radius of $\mathrm{0.3697\pm0.0018\,R_\odot}$, an effective temperature of $\mathrm{3389 \, K}$, and a J-band magnitude of $\mathrm{11.706\pm0.025}$. Current planet formation models do not predict the existence of gas giants such as TOI-3235 b around such low-mass stars. With a high transmission spectroscopy metric, TOI-3235 b is one of the best-suited giants orbiting M-dwarfs for atmospheric characterization., 15 pages, 4 figures. Accepted for publication in APJL

Published
2023

6. PTFO 8-8695: Two Stars, Two Signals, No Planet

Author

Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology. Department of Aeronautics and Astronautics, Bouma, LG, Winn, JN, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Jenkins, JM, Barclay, T, Collins, KA, Doty, JP, Louie, DR, Quinn, SN, Rose, ME, Smith, JC, Villaseñor, J, Wohler, B, Massachusetts Institute of Technology. Department of Physics, MIT Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology. Department of Aeronautics and Astronautics, Bouma, LG, Winn, JN, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Jenkins, JM, Barclay, T, Collins, KA, Doty, JP, Louie, DR, Quinn, SN, Rose, ME, Smith, JC, Villaseñor, J, and Wohler, B

Abstract

© 2020. The American Astronomical Society. All rights reserved.. PTFO 8-8695 (CVSO 30) is a star in the 7-10 million year old Orion OB1a cluster that shows brightness dips that resemble planetary transits. Although strong evidence against the planet hypothesis has been presented, the possibility remains debated in the literature. To obtain further clues, we inspected data from the NASA Transiting Exoplanet Survey Satellite (TESS) and the ESA Gaia mission. The Gaia data suggest that PTFO 8-8695 is a binary: the photometric data show it to be overluminous with respect to members of its kinematic group, and the astrometric data are inconsistent with a single star. The TESS light curve shows two different photometric periods. The variability is dominated by a sinusoidal signal with a period of 11.98 hr, presumably caused by stellar rotation. Also present is a 10.76 hr signal consisting of a not-quite sinusoid interrupted by hour-long dips, the type of signal previously interpreted as planetary transits. The phase of the dips is nearly 180 away from the phase of the originally reported dips. As noted previously, this makes them difficult to explain as planetary transits. Instead, we believe that PTFO 8-8695 is a pair of young and rapidly rotating M dwarfs, one of which shows the same "transient-dipper"behavior that has been seen in at least five other cases. The origin of these transient dips is still unknown but likely involves circumstellar material.

Published
2022

7. HD 56414 b: A Warm Neptune Transiting an A-type Star

Author

Giacalone, S, Dressing, CD, Muñoz, AG, Hooton, MJ, Stassun, KG, Quinn, SN, Zhou, G, Ziegler, C, Vanderspek, R, Latham, DW, Seager, S, Winn, JN, Jenkins, JM, Briceño, C, Huang, CX, Rodriguez, DR, Shporer, A, Mann, AW, Watanabe, D, Wohler, B, Giacalone, S [0000-0002-8965-3969], Dressing, CD [0000-0001-8189-0233], Muñoz, AG [0000-0003-1756-4825], Hooton, MJ [0000-0003-0030-332X], Stassun, KG [0000-0002-3481-9052], Quinn, SN [0000-0002-8964-8377], Zhou, G [0000-0002-4891-3517], Ziegler, C [0000-0002-0619-7639], Vanderspek, R [0000-0001-6763-6562], Latham, DW [0000-0001-9911-7388], Seager, S [0000-0002-6892-6948], Winn, JN [0000-0002-4265-047X], Jenkins, JM [0000-0002-4715-9460], Briceño, C [0000-0001-7124-4094], Huang, CX [0000-0003-0918-7484], Rodriguez, DR [0000-0003-1286-5231], Shporer, A [0000-0002-1836-3120], Mann, AW [0000-0003-3654-1602], Watanabe, D [0000-0002-3555-8464], Wohler, B [0000-0002-5402-9613], Apollo - University of Cambridge Repository, Astrophysique Interprétation Modélisation (AIM (UMR_7158 / UMR_E_9005 / UM_112)), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Exoplanet astronomy, Exoplanet evolution, FOS: Physical sciences, Astronomy and Astrophysics, 5109 Space Sciences, Transits, [SDU]Sciences of the Universe [physics], 5101 Astronomical Sciences, Space and Planetary Science, Exoplanet systems, 51 Physical Sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

We report the discovery in TESS data and validation of HD 56414 b (a.k.a. TOI-1228 b), a Neptune-size ($R_{\rm p} = 3.71 \pm 0.20\, R_\oplus$) planet with a 29-day orbital period transiting a young (Age = $420 \pm 140$ Myr) A-type star in the TESS southern continuous viewing zone. HD 56414 is one of the hottest stars ($T_{\rm eff} = 8500 \pm 150 \, {\rm K}$) to host a known sub-Jovian planet. HD 56414 b lies on the boundary of the hot Neptune desert in planet radius -- bolometric insolation flux space, suggesting that the planet may be experiencing mass loss. To explore this, we apply a photoevaporation model that incorporates the high near ultraviolet continuum emission of A-type stars. We find that the planet can retain most of its atmosphere over the typical 1-Gyr main sequence lifetime of an A-type star if its mass is $\ge 8 \, M_\oplus$. Our model also predicts that close-in Neptune-size planets with masses $< 14 \, M_\oplus$ are susceptible to total atmospheric stripping over 1 Gyr, hinting that the hot Neptune desert, which has been previously observed around FGKM-type stars, likely extends to A-type stars., 12 pages, 4 figures, 1 table

Published
2022

8. Investigating the architecture and internal structure of the TOI-561 system planets with CHEOPS, HARPS-N, and TESS

Author

Lacedelli, G, Wilson, TG, Malavolta, L, Hooton, MJ, Collier Cameron, A, Alibert, Y, Mortier, A, Bonfanti, A, Haywood, RD, Hoyer, S, Piotto, G, Bekkelien, A, Vanderburg, AM, Benz, W, Dumusque, X, Deline, A, Lopez-Morales, M, Borsato, L, Rice, K, Fossati, L, Latham, DW, Brandeker, A, Poretti, E, Sousa, SG, Sozzetti, A, Salmon, S, Burke, CJ, Van Grootel, V, Fausnaugh, MM, Adibekyan, V, Huang, CX, Osborn, HP, Mustill, AJ, Palle, E, Bourrier, V, Nascimbeni, V, Alonso, R, Anglada, G, Barczy, T, Barrado Y Navascues, D, Barros, SCC, Baumjohann, W, Beck, M, Beck, T, Billot, N, Bonfils, X, Broeg, C, Buchhave, LA, Cabrera, J, Charnoz, S, Cosentino, R, Csizmadia, S, Davies, MB, Deleuil, M, Delrez, L, Demangeon, O, Demory, BO, Ehrenreich, D, Erikson, A, Esparza-Borges, E, Floren, HG, Fortier, A, Fridlund, M, Futyan, D, Gandolfi, D, Ghedina, A, Gillon, M, Güdel, M, Guterman, P, Harutyunyan, A, Heng, K, Isaak, KG, Jenkins, JM, Kiss, L, Laskar, J, Lecavelier Des Etangs, A, Lendl, M, Lovis, C, Magrin, D, Marafatto, L, Martinez Fiorenzano, AF, Maxted, PFL, Mayor, M, Micela, G, Molinari, E, Murgas, F, Narita, N, Olofsson, G, Ottensamer, R, Pagano, I, Pasetti, A, Pedani, M, Pepe, FA, Peter, G, Phillips, DF, Pollacco, D, Queloz, D, Ragazzoni, R, Rando, N, Ratti, F, Lacedelli, G [0000-0002-4197-7374], Wilson, TG [0000-0001-8749-1962], Malavolta, L [0000-0002-6492-2085], Hooton, MJ [0000-0003-0030-332X], Collier Cameron, A [0000-0002-8863-7828], Mortier, A [0000-0001-7254-4363], Borsato, L [0000-0003-0066-9268], Rice, K [0000-0002-6379-9185], Sousa, SG [0000-0001-9047-2965], Sozzetti, A [0000-0002-7504-365X], Osborn, HP [0000-0002-4047-4724], Mustill, AJ [0000-0002-2086-3642], Nascimbeni, V [0000-0001-9770-1214], Buchhave, LA [0000-0003-1605-5666], Csizmadia, S [0000-0001-6803-9698], Delrez, L [0000-0001-6108-4808], Gandolfi, D [0000-0001-8627-9628], Lendl, M [0000-0001-9699-1459], Maxted, PFL [0000-0003-3794-1317], and Apollo - University of Cambridge Repository

Subjects
techniques: photometric, stars: individual: TOI-561 (TIC 377064495, Gaia EDR3 3850421005290172416), techniques: radial velocities, planets and satellites: fundamental parameters, planets and satellites: interiors
Abstract

We present a precise characterization of the TOI-561 planetary system obtained by combining previously published data with TESS and CHEOPS photometry, and a new set of $62$ HARPS-N radial velocities (RVs). Our joint analysis confirms the presence of four transiting planets, namely TOI-561 b ($P = 0.45$ d, $R = 1.42$ R$_\oplus$, $M = 2.0$ M$_\oplus$), c ($P = 10.78$ d, $R = 2.91$ R$_\oplus$, $M = 5.4$ M$_\oplus$), d ($P = 25.7$ d, $R = 2.82$ R$_\oplus$, $M = 13.2$ M$_\oplus$) and e ($P = 77$ d, $R = 2.55$ R$_\oplus$, $M = 12.6$ M$_\oplus$). Moreover, we identify an additional, long-period signal ($>450$ d) in the RVs, which could be due to either an external planetary companion or to stellar magnetic activity. The precise masses and radii obtained for the four planets allowed us to conduct interior structure and atmospheric escape modelling. TOI-561 b is confirmed to be the lowest density ($\rho_{\rm b} = 3.8 \pm 0.5$ g cm$^{-3}$) ultra-short period (USP) planet known to date, and the low metallicity of the host star makes it consistent with the general bulk density-stellar metallicity trend. According to our interior structure modelling, planet b has basically no gas envelope, and it could host a certain amount of water. In contrast, TOI-561 c, d, and e likely retained an H/He envelope, in addition to a possibly large water layer. The inferred planetary compositions suggest different atmospheric evolutionary paths, with planets b and c having experienced significant gas loss, and planets d and e showing an atmospheric content consistent with the original one. The uniqueness of the USP planet, the presence of the long-period planet TOI-561 e, and the complex architecture make this system an appealing target for follow-up studies.

Published
2022

9. Toi-1235 b: A keystone super-earth for testing radius valley emergence models around early m dwarfs

Author

Cloutier, R, Rodriguez, JE, Irwin, J, Charbonneau, D, Stassun, KG, Mortier, A, Latham, DW, Isaacson, H, Howard, AW, Udry, S, Wilson, TG, Watson, CA, Pinamonti, M, Lienhard, F, Giacobbe, P, Guerra, P, Collins, KA, Beiryla, A, Esquerdo, GA, Matthews, E, Matson, RA, Howell, SB, Furlan, E, Crossfield, IJM, Winters, JG, Nava, C, Ment, K, Lopez, ED, Ricker, G, Vanderspek, R, Seager, S, Jenkins, JM, Ting, EB, Tenenbaum, P, Sozzetti, A, Sha, L, Ségransan, D, Schlieder, JE, Sasselov, D, Roy, A, Robertson, P, Rice, K, Poretti, E, Piotto, G, Phillips, D, Pepper, J, Pepe, F, Molinari, E, Mocnik, T, Micela, G, Mayor, M, Martinez Fiorenzano, AF, Mallia, F, Lubin, J, Lovis, C, López-Morales, M, Kosiarek, MR, Kielkopf, JF, Kane, Jensen, ELN, Isopi, G, Huber, D, Hill, ML, Harutyunyan, A, Gonzales, E, Giacalone, S, Ghedina, A, Ercolino, A, Dumusque, X, Dressing, CD, Damasso, M, Dalba, PA, Cosentino, R, Conti, DM, Colón, KD, Collins, KI, Cameron, AC, Ciardi, D, Christiansen, J, Chontos, A, Cecconi, M, Caldwell, DA, Burke, C, Buchhave, L, Beichman, C, Behmard, A, Beard, C, Akana Murphy, JM, Cloutier, R [0000-0001-5383-9393], Rodriguez, JE [0000-0001-8812-0565], Charbonneau, D [0000-0002-9003-484X], Stassun, KG [0000-0002-3481-9052], Mortier, A [0000-0001-7254-4363], Latham, DW [0000-0001-9911-7388], Isaacson, H [0000-0002-0531-1073], Howard, AW [0000-0001-8638-0320], Udry, S [0000-0001-7576-6236], Collins, KA [0000-0001-6588-9574], Beiryla, A [0000-0001-6637-5401], Esquerdo, GA [0000-0002-9789-5474], Matthews, E [0000-0003-0593-1560], Matson, RA [0000-0001-7233-7508], Howell, SB [0000-0002-2532-2853], Winters, JG [0000-0001-6031-9513], Nava, C [0000-0001-8838-3883], Ment, K [0000-0001-5847-9147], Ricker, G [0000-0003-2058-6662], Vanderspek, R [0000-0001-6763-6562], Seager, S [0000-0002-6892-6948], Jenkins, JM [0000-0002-4715-9460], Ting, EB [0000-0002-8219-9505], Tenenbaum, P [0000-0002-1949-4720], Sozzetti, A [0000-0002-7504-365X], Sha, L [0000-0001-5401-8079], Ségransan, D [0000-0003-2355-8034], Schlieder, JE [0000-0001-5347-7062], Sasselov, D [0000-0001-7014-1771], Roy, A [0000-0001-8127-5775], Robertson, P [0000-0003-0149-9678], Poretti, E [0000-0003-1200-0473], Piotto, G [0000-0002-9937-6387], Pepper, J [0000-0002-3827-8417], Molinari, E [0000-0002-1742-7735], Mocnik, T [0000-0003-4603-556X], Micela, G [0000-0002-9900-4751], Lubin, J [0000-0001-8342-7736], López-Morales, M [0000-0003-3204-8183], Kielkopf, JF [0000-0003-0497-2651], Kane, SR [0000-0002-7084-0529], Jensen, ELN [0000-0002-4625-7333], Huber, D [0000-0001-8832-4488], Hill, ML [0000-0002-0139-4756], Giacalone, S [0000-0002-8965-3969], Ghedina, A [0000-0003-4702-5152], Dumusque, X [0000-0002-9332-2011], Dressing, CD [0000-0001-8189-0233], Dalba, PA [0000-0002-4297-5506], Cosentino, R [0000-0003-1784-1431], Conti, DM [0000-0003-2239-0567], Colón, KD [0000-0001-8020-7121], Collins, KI [0000-0003-2781-3207], Ciardi, D [0000-0002-5741-3047], Christiansen, J [0000-0002-8035-4778], Chontos, A [0000-0003-1125-2564], Caldwell, DA [0000-0003-1963-9616], Burke, C [0000-0002-7754-9486], Buchhave, L [0000-0003-1605-5666], Behmard, A [0000-0003-0012-9093], Beard, C [0000-0001-7708-2364], Akana Murphy, JM [0000-0001-8898-8284], and Apollo - University of Cambridge Repository

Subjects
Radial velocity, Exoplanet formation, Transit photometry, M dwarf stars, Exoplanet structure
Abstract

Small planets on close-in orbits tend to exhibit envelope mass fractions of either effectively zero or up to a few percent depending on their size and orbital period. Models of thermally-driven atmospheric mass loss and of terrestrial planet formation in a gas-poor environment make distinct predictions regarding the location of this rocky/non-rocky transition in period-radius space. Here we present the confirmation of TOI-1235 b ($P=3.44$ days, $r_p=1.738^{+0.087}_{-0.076}$ R$_{\oplus}$), a planet whose size and period are intermediate between the competing model predictions, thus making the system an important test case for emergence models of the rocky/non-rocky transition around early M dwarfs ($R_s=0.630\pm 0.015$ R$_{\odot}$, $M_s=0.640\pm 0.016$ M$_{\odot}$). We confirm the TESS planet discovery using reconnaissance spectroscopy, ground-based photometry, high-resolution imaging, and a set of 38 precise radial-velocities from HARPS-N and HIRES. We measure a planet mass of $6.91^{+0.75}_{-0.85}$ M$_{\oplus}$ which implies an iron core mass fraction of $20^{+15}_{-12}$% in the absence of a gaseous envelope. The bulk composition of TOI-1235 b is therefore consistent with being Earth-like and we constrain a H/He envelope mass fraction to be $

Published
2020

10. PTFO 8-8695: Two Stars, Two Signals, No Planet

Author

Bouma, LG, Winn, JN, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Jenkins, JM, Barclay, T, Collins, KA, Doty, JP, Louie, DR, Quinn, SN, Rose, ME, Smith, JC, Villaseñor, J, Wohler, B, Bouma, LG, Winn, JN, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Jenkins, JM, Barclay, T, Collins, KA, Doty, JP, Louie, DR, Quinn, SN, Rose, ME, Smith, JC, Villaseñor, J, and Wohler, B

Abstract

© 2020. The American Astronomical Society. All rights reserved.. PTFO 8-8695 (CVSO 30) is a star in the 7-10 million year old Orion OB1a cluster that shows brightness dips that resemble planetary transits. Although strong evidence against the planet hypothesis has been presented, the possibility remains debated in the literature. To obtain further clues, we inspected data from the NASA Transiting Exoplanet Survey Satellite (TESS) and the ESA Gaia mission. The Gaia data suggest that PTFO 8-8695 is a binary: the photometric data show it to be overluminous with respect to members of its kinematic group, and the astrometric data are inconsistent with a single star. The TESS light curve shows two different photometric periods. The variability is dominated by a sinusoidal signal with a period of 11.98 hr, presumably caused by stellar rotation. Also present is a 10.76 hr signal consisting of a not-quite sinusoid interrupted by hour-long dips, the type of signal previously interpreted as planetary transits. The phase of the dips is nearly 180 away from the phase of the originally reported dips. As noted previously, this makes them difficult to explain as planetary transits. Instead, we believe that PTFO 8-8695 is a pair of young and rapidly rotating M dwarfs, one of which shows the same "transient-dipper"behavior that has been seen in at least five other cases. The origin of these transient dips is still unknown but likely involves circumstellar material.

Published
2021

11. The TESS-keck survey. III. A stellar obliquity measurement of TOI-1726 c

Author

Dai, F, Dai, F, Roy, A, Fulton, B, Robertson, P, Hirsch, L, Isaacson, H, Albrecht, S, Mann, AW, Kristiansen, MH, Batalha, NM, Beard, C, Behmard, A, Chontos, A, Crossfield, IJM, Dalba, PA, Dressing, C, Giacalone, S, Hill, M, Howard, AW, Huber, D, Kane, SR, Kosiarek, M, Lubin, J, Mayo, A, Mocnik, T, Akana Murphy, JM, Petigura, EA, Rosenthal, L, Rubenzahl, RA, Scarsdale, N, Weiss, LM, van Zandt, J, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Winn, JN, Jenkins, JM, Caldwell, DA, Charbonneau, D, Daylan, T, Günther, MN, Morgan, E, Quinn, SN, Rose, ME, Smith, JC, Dai, F, Dai, F, Roy, A, Fulton, B, Robertson, P, Hirsch, L, Isaacson, H, Albrecht, S, Mann, AW, Kristiansen, MH, Batalha, NM, Beard, C, Behmard, A, Chontos, A, Crossfield, IJM, Dalba, PA, Dressing, C, Giacalone, S, Hill, M, Howard, AW, Huber, D, Kane, SR, Kosiarek, M, Lubin, J, Mayo, A, Mocnik, T, Akana Murphy, JM, Petigura, EA, Rosenthal, L, Rubenzahl, RA, Scarsdale, N, Weiss, LM, van Zandt, J, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Winn, JN, Jenkins, JM, Caldwell, DA, Charbonneau, D, Daylan, T, Günther, MN, Morgan, E, Quinn, SN, Rose, ME, and Smith, JC

Abstract

We report the measurement of a spectroscopic transit of TOI-1726c, one of two planets transiting a G-type star with V = 6.9 in the Ursa Major Moving Group (∼400 Myr). With a precise age constraint from cluster membership, TOI-1726 provides a great opportunity to test various obliquity excitation scenarios that operate on different timescales. By modeling the Rossiter-McLaughlin (RM) effect, we derived a sky-projected obliquity of -1-+3235∘. This result rules out a polar/retrograde orbit and is consistent with an aligned orbit for planet c. Considering the previously reported, similarly prograde RM measurement of planet b and the transiting nature of both planets, TOI-1726 tentatively conforms to the overall picture that compact multitransiting planetary systems tend to have coplanar, likely aligned orbits. TOI-1726 is also a great atmospheric target for understanding differential atmospheric loss of sub-Neptune planets (planet b 2.2 R☉ and c 2.7 R☉ both likely underwent photoevaporation). The coplanar geometry points to a dynamically cold history of the system that simplifies any future modeling of atmospheric escape.

Published
2020

12. The TESS-Keck Survey. I. A Warm Sub-Saturn-mass Planet and a Caution about Stray Light in TESS Cameras

Author

Dalba, PA, Dalba, PA, Gupta, AF, Rodriguez, JE, Dragomir, D, Huang, CX, Kane, SR, Quinn, SN, Bieryla, A, Esquerdo, GA, Fulton, BJ, Scarsdale, N, Batalha, NM, Beard, C, Behmard, A, Chontos, A, Crossfield, IJM, Dressing, CD, Giacalone, S, Hill, ML, Hirsch, LA, Howard, AW, Huber, D, Isaacson, H, Kosiarek, M, Lubin, J, Mayo, AW, Mocnik, T, Akana Murphy, JM, Petigura, EA, Robertson, P, Rosenthal, LJ, Roy, A, Rubenzahl, RA, Van Zandt, J, Weiss, LM, Knudstrup, E, Andersen, MF, Grundahl, F, Yao, X, Pepper, J, Villanueva, S, Ciardi, DR, Cloutier, R, Jacobs, TL, Kristiansen, MH, Lacourse, DM, Lendl, M, Osborn, HP, Palle, E, Stassun, KG, Stevens, DJ, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Winn, JN, Jenkins, JM, Caldwell, DA, Daylan, T, Fong, W, Goeke, RF, Rose, ME, Rowden, P, Schlieder, JE, Smith, JC, Vanderburg, A, Dalba, PA, Dalba, PA, Gupta, AF, Rodriguez, JE, Dragomir, D, Huang, CX, Kane, SR, Quinn, SN, Bieryla, A, Esquerdo, GA, Fulton, BJ, Scarsdale, N, Batalha, NM, Beard, C, Behmard, A, Chontos, A, Crossfield, IJM, Dressing, CD, Giacalone, S, Hill, ML, Hirsch, LA, Howard, AW, Huber, D, Isaacson, H, Kosiarek, M, Lubin, J, Mayo, AW, Mocnik, T, Akana Murphy, JM, Petigura, EA, Robertson, P, Rosenthal, LJ, Roy, A, Rubenzahl, RA, Van Zandt, J, Weiss, LM, Knudstrup, E, Andersen, MF, Grundahl, F, Yao, X, Pepper, J, Villanueva, S, Ciardi, DR, Cloutier, R, Jacobs, TL, Kristiansen, MH, Lacourse, DM, Lendl, M, Osborn, HP, Palle, E, Stassun, KG, Stevens, DJ, Ricker, GR, Vanderspek, R, Latham, DW, Seager, S, Winn, JN, Jenkins, JM, Caldwell, DA, Daylan, T, Fong, W, Goeke, RF, Rose, ME, Rowden, P, Schlieder, JE, Smith, JC, and Vanderburg, A

Abstract

We report the detection of a Saturn-size exoplanet orbiting HD 332231 (TOI 1456) in light curves from the Transiting Exoplanet Survey Satellite (TESS). HD 332231 - an F8 dwarf star with a V-band magnitude of 8.56 - was observed by TESS in Sectors 14 and 15. We detect a single-transit event in the Sector 15 presearch data conditioning (PDC) light curve. We obtain spectroscopic follow-up observations of HD 332231 with the Automated Planet Finder, Keck I, and SONG telescopes. The orbital period we infer from radial velocity (RV) observations leads to the discovery of another transit in Sector 14 that was masked by PDC due to scattered light contamination. A joint analysis of the transit and RV data confirms the planetary nature of HD 332231 b, a Saturn-size (0.867-0.025+0.027RJ), sub-Saturn-mass (0.244±0.021MJ) exoplanet on a 18.71 day circular orbit. The low surface gravity of HD 332231 b and the relatively low stellar flux it receives make it a compelling target for transmission spectroscopy. Also, the stellar obliquity is likely measurable via the Rossiter-McLaughlin effect, an exciting prospect given the 0.14 au orbital separation of HD 332231 b. The spectroscopic observations do not provide substantial evidence for any additional planets in the HD 332231 system, but continued RV monitoring is needed to further characterize this system. We also predict that the frequency and duration of masked data in the PDC light curves for TESS Sectors 14-16 could hide transits of some exoplanets with orbital periods between 10.5 and 17.5 days.

Published
2020

13. HD 202772A b: A Transiting Hot Jupiter around a Bright, Mildly Evolved Star in a Visual Binary Discovered by TESS

Author

Wang, S, Wang, S, Jones, M, Shporer, A, Fulton, BJ, Paredes, LA, Trifonov, T, Kossakowski, D, Eastman, J, Redfield, S, Günther, MN, Kreidberg, L, Huang, CX, Millholland, S, Seligman, D, Fischer, D, Brahm, R, Wang, XY, Cruz, B, Henry, T, James, HS, Addison, B, Liang, ES, Davis, AB, Tronsgaard, R, Worku, K, Brewer, JM, Kürster, M, Zhang, H, Beichman, CA, Bieryla, A, Brown, TM, Christiansen, JL, Ciardi, DR, Collins, KA, Esquerdo, GA, Howard, AW, Isaacson, H, Latham, DW, Mazeh, T, Petigura, EA, Quinn, SN, Shahaf, S, Siverd, RJ, Rodler, F, Reffert, S, Zakhozhay, O, Ricker, GR, Vanderspek, R, Seager, S, Winn, JN, Jenkins, JM, Boyd, PT, Frész, G, Henze, C, Levine, AM, Morris, R, Paegert, M, Stassun, KG, Ting, EB, Vezie, M, Laughlin, G, Wang, S, Wang, S, Jones, M, Shporer, A, Fulton, BJ, Paredes, LA, Trifonov, T, Kossakowski, D, Eastman, J, Redfield, S, Günther, MN, Kreidberg, L, Huang, CX, Millholland, S, Seligman, D, Fischer, D, Brahm, R, Wang, XY, Cruz, B, Henry, T, James, HS, Addison, B, Liang, ES, Davis, AB, Tronsgaard, R, Worku, K, Brewer, JM, Kürster, M, Zhang, H, Beichman, CA, Bieryla, A, Brown, TM, Christiansen, JL, Ciardi, DR, Collins, KA, Esquerdo, GA, Howard, AW, Isaacson, H, Latham, DW, Mazeh, T, Petigura, EA, Quinn, SN, Shahaf, S, Siverd, RJ, Rodler, F, Reffert, S, Zakhozhay, O, Ricker, GR, Vanderspek, R, Seager, S, Winn, JN, Jenkins, JM, Boyd, PT, Frész, G, Henze, C, Levine, AM, Morris, R, Paegert, M, Stassun, KG, Ting, EB, Vezie, M, and Laughlin, G

Abstract

We report the first confirmation of a hot Jupiter discovered by the Transiting Exoplanet Survey Satellite (TESS) mission: HD 202772A b. The transit signal was detected in the data from TESS Sector 1, and was confirmed to be of planetary origin through radial velocity (RV) measurements. HD 202772A b is orbiting a mildly evolved star with a period of 3.3 days. With an apparent magnitude of V = 8.3, the star is among the brightest and most massive known to host a hot Jupiter. Based on the 27 days of TESS photometry and RV data from the CHIRON, HARPS, and Tillinghast Reflector Echelle Spectrograph, the planet has a mass of and radius of , making it an inflated gas giant. HD 202772A b is a rare example of a transiting hot Jupiter around a quickly evolving star. It is also one of the most strongly irradiated hot Jupiters currently known.

Published
2019

14. A Super-Earth and Sub-Neptune Transiting the Late-type M Dwarf LP 791-18

Author

Crossfield, IJM, Crossfield, IJM, Waalkes, W, Newton, ER, Narita, N, Muirhead, P, Ment, K, Matthews, E, Kraus, A, Kostov, V, Kosiarek, MR, Kane, SR, Isaacson, H, Halverson, S, Gonzales, E, Everett, M, Dragomir, D, Collins, KA, Chontos, A, Berardo, D, Winters, JG, Winn, JN, Scott, NJ, Rojas-Ayala, B, Rizzuto, AC, Petigura, EA, Peterson, M, Mocnik, T, Mikal-Evans, T, Mehrle, N, Matson, R, Kuzuhara, M, Irwin, J, Huber, D, Huang, C, Howell, S, Howard, AW, Hirano, T, Fulton, BJ, Dupuy, T, Dressing, CD, Dalba, PA, Charbonneau, D, Burt, J, Berta-Thompson, Z, Benneke, B, Watanabe, N, Twicken, JD, Tamura, M, Schlieder, J, Seager, S, Rose, ME, Ricker, G, Quintana, E, Lépine, S, Latham, DW, Kotani, T, Jenkins, JM, Hori, Y, Colon, K, Caldwell, DA, Crossfield, IJM, Crossfield, IJM, Waalkes, W, Newton, ER, Narita, N, Muirhead, P, Ment, K, Matthews, E, Kraus, A, Kostov, V, Kosiarek, MR, Kane, SR, Isaacson, H, Halverson, S, Gonzales, E, Everett, M, Dragomir, D, Collins, KA, Chontos, A, Berardo, D, Winters, JG, Winn, JN, Scott, NJ, Rojas-Ayala, B, Rizzuto, AC, Petigura, EA, Peterson, M, Mocnik, T, Mikal-Evans, T, Mehrle, N, Matson, R, Kuzuhara, M, Irwin, J, Huber, D, Huang, C, Howell, S, Howard, AW, Hirano, T, Fulton, BJ, Dupuy, T, Dressing, CD, Dalba, PA, Charbonneau, D, Burt, J, Berta-Thompson, Z, Benneke, B, Watanabe, N, Twicken, JD, Tamura, M, Schlieder, J, Seager, S, Rose, ME, Ricker, G, Quintana, E, Lépine, S, Latham, DW, Kotani, T, Jenkins, JM, Hori, Y, Colon, K, and Caldwell, DA

Abstract

Planets occur most frequently around cool dwarfs, but only a handful of specific examples are known to orbit the latest-type M stars. Using TESS photometry, we report the discovery of two planets transiting the low-mass star called LP 791-18 (identified by TESS as TOI 736). This star has spectral type M6V, effective temperature 2960 K, and radius 0.17 R o, making it the third-coolest star known to host planets. The two planets straddle the radius gap seen for smaller exoplanets; they include a 1.1R ⊕ planet on a 0.95 day orbit and a 2.3R ⊕ planet on a 5 day orbit. Because the host star is small the decrease in light during these planets' transits is fairly large (0.4% and 1.7%). This has allowed us to detect both planets' transits from ground-based photometry, refining their radii and orbital ephemerides. In the future, radial velocity observations and transmission spectroscopy can both probe these planets' bulk interior and atmospheric compositions, and additional photometric monitoring would be sensitive to even smaller transiting planets.

Published
2019

15. The Mass of the White Dwarf Companion in the Self-lensing Binary KOI-3278: Einstein versus Newton

Author

Yahalomi, DA, Yahalomi, DA, Shvartzvald, Y, Agol, E, Shporer, A, Latham, DW, Kruse, E, Brewer, JM, Buchhave, LA, Fulton, BJ, Howard, AW, Isaacson, H, Petigura, EA, Quinn, SN, Yahalomi, DA, Yahalomi, DA, Shvartzvald, Y, Agol, E, Shporer, A, Latham, DW, Kruse, E, Brewer, JM, Buchhave, LA, Fulton, BJ, Howard, AW, Isaacson, H, Petigura, EA, and Quinn, SN

Abstract

KOI-3278 is a self-lensing stellar binary consisting of a white dwarf secondary orbiting a Sun-like primary star. Kruse & Agol noticed small periodic brightenings every 88.18 days in the Kepler photometry and interpreted these as the result of microlensing by a white dwarf with about 63% of the mass of the Sun. We obtained two sets of spectra for the primary that allowed us to derive three sets of spectroscopic estimates for its effective temperature, surface gravity, and metallicity for the first time. We used these values to update the Kruse & Agol Einsteinian microlensing model, resulting in a revised mass for the white dwarf of 0.539-0.020+0.022 M o. The spectra also allowed us to determine radial velocities and derive orbital solutions, with good agreement between the two independent data sets. An independent Newtonian dynamical MCMC model of the combined velocities yielded a mass for the white dwarf of 0.5122-0.0058+0.0057 M o. The nominal uncertainty for the Newtonian mass is about four times better than for the Einsteinian, ± 1.1% versus ± 4.1%, and the difference between the two mass determinations is 5.2%. We then present a joint Einsteinian microlensing and Newtonian radial velocity model for KOI-3278, which yielded a mass for the white dwarf of 0.5250-0.0089+0.0082M o. This joint model does not rely on any white dwarf evolutionary models or assumptions on the white dwarf mass-radius relation. We discuss the benefits of a joint model of self-lensing binaries, and how future studies of these systems can provide insight into the mass-radius relation of white dwarfs.

Published
2019

16. The broadband and spectrally resolved H-band Eclipse of KELT-1b and the Role of Surface Gravity in Stratospheric Inversions in Hot Jupiters

Author

Beatty, TG, Madhusudhan, N, Pogge, R, Chung, SM, Bierlya, A, Gaudi, BS, Latham, DW, Nikku, Madhusudhan [0000-0002-4869-000X], and Apollo - University of Cambridge Repository

Subjects
planets and satellites: atmospheres, techniques: imaging spectroscopy, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, brown dwarfs
Abstract

We present a high precision H-band emission spectrum of the transiting brown dwarf KELT-1b, which we spectrophotometrically observed during a single secondary eclipse using the LUCI1 multi-object spectrograph on the Large Binocular Telescope. Using a Gaussian-process regression model, we are able to clearly measure the broadband eclipse depth as Delta-H=1418+/-94ppm. We are also able to spectrally-resolve the H-band into five separate wavechannels and measure the eclipse spectrum of KELT-1b at R~50 with an average precision of +/-135ppm. We find that the day side has an average brightness temperature of 3250+/-50K, with significant variation as a function of wavelength. Based on our observations, and previous measurements of KELT-1b's eclipse at other wavelengths, we find that KELT-1b's day side appears identical to an isolated 3200K brown dwarf, and our modeling of the atmospheric emission shows a monotonically decreasing temperature-pressure profile. This is in contrast to hot Jupiters with similar day side brightness temperatures near 3000K, all of which appear to be either isothermal or posses a stratospheric temperature inversion. We hypothesize that the lack of an inversion in KELT-1b is due to its high surface gravity, which we argue could be caused by the increased efficiency of cold-trap processes within its atmosphere.

Published
2018
Full Text
View/download PDF

17. A 2 R ⊕ Planet Orbiting the Bright Nearby K Dwarf Wolf 503

Author

Peterson, MS, Peterson, MS, Benneke, B, David, TJ, Dressing, CD, Ciardi, D, Crossfield, IJM, Schlieder, JE, Petigura, EA, Mamajek, EE, Christiansen, JL, Quinn, SN, Fulton, BJ, Howard, AW, Sinukoff, E, Beichman, C, Latham, DW, Yu, L, Arango, N, Shporer, A, Henning, T, Huang, CX, Kosiarek, MR, Dittmann, J, Isaacson, H, Peterson, MS, Peterson, MS, Benneke, B, David, TJ, Dressing, CD, Ciardi, D, Crossfield, IJM, Schlieder, JE, Petigura, EA, Mamajek, EE, Christiansen, JL, Quinn, SN, Fulton, BJ, Howard, AW, Sinukoff, E, Beichman, C, Latham, DW, Yu, L, Arango, N, Shporer, A, Henning, T, Huang, CX, Kosiarek, MR, Dittmann, J, and Isaacson, H

Abstract

Since its launch in 2009, the Kepler telescope has found thousands of planets with radii between that of Earth and Neptune. Recent studies of the distribution of these planets have revealed a gap in the population near 1.5-2.0 R ⊕, informally dividing these planets into "super-Earths" and "sub-Neptunes." The origin of this division is difficult to investigate directly because the majority of planets found by Kepler orbit distant, dim stars and are not amenable to radial velocity follow-up or transit spectroscopy, making bulk density and atmospheric measurements difficult. Here, we present the discovery and validation of a newly found planet in direct proximity to the radius gap, orbiting the bright (J = 8.32 mag), nearby (D = 44.5 pc) high proper motion K3.5V star Wolf 503 (EPIC 212779563). We determine the possibility of a companion star and false positive detection to be extremely low using both archival images and high-contrast adaptive optics images from the Palomar observatory. The brightness of the host star makes Wolf 503b a prime target for prompt radial velocity follow-up, and with the small stellar radius (0.690 ± 0.025R o), it is also an excellent target for HST transit spectroscopy and detailed atmospheric characterization with JWST. With its measured radius near the gap in the planet radius and occurrence rate distribution, Wolf 503b offers a key opportunity to better understand the origin of this radius gap as well as the nature of the intriguing populations of "super-Earths" and "sub-Neptunes" as a whole.

Published
2018

18. Two Warm, Low-density Sub-Jovian Planets Orbiting Bright Stars in K2 Campaigns 13 and 14

Author

Yu, L, Yu, L, Rodriguez, JE, Eastman, JD, Crossfield, IJM, Shporer, A, Gaudi, BS, Burt, J, Fulton, BJ, Sinukoff, E, Howard, AW, Isaacson, H, Kosiarek, MR, Ciardi, DR, Schlieder, JE, Penev, K, Vanderburg, A, Stassun, KG, Bieryla, A, Butler, RP, Berlind, P, Calkins, ML, Esquerdo, GA, Latham, DW, Murawski, G, Stevens, DJ, Petigura, EA, Kreidberg, L, Bristow, M, Yu, L, Yu, L, Rodriguez, JE, Eastman, JD, Crossfield, IJM, Shporer, A, Gaudi, BS, Burt, J, Fulton, BJ, Sinukoff, E, Howard, AW, Isaacson, H, Kosiarek, MR, Ciardi, DR, Schlieder, JE, Penev, K, Vanderburg, A, Stassun, KG, Bieryla, A, Butler, RP, Berlind, P, Calkins, ML, Esquerdo, GA, Latham, DW, Murawski, G, Stevens, DJ, Petigura, EA, Kreidberg, L, and Bristow, M

Abstract

We report the discovery of two planets transiting the bright stars HD 89345 (EPIC 248777106, V = 9.376, K = 7.721) in K2 Campaign 14 and HD 286123 (EPIC 247098361, V = 9.822, K = 8.434) in K2 Campaign 13. Both stars are G-Type stars, one of which is at or near the end of its main-sequence lifetime, and the other is just over halfway through its main-sequence lifetime. HD 89345 hosts a warm sub-Saturn (0.66 , 0.11 , = 1100 K) in an 11.81 day orbit. The planet is similar in size to WASP-107b, which falls in the transition region between ice giants and gas giants. HD 286123 hosts a Jupiter-sized, low-mass planet (1.06 , 0.39 , = 1000 K) in an 11.17 day, mildly eccentric orbit, with e = 0.255 ± 0.035. Given that they orbit relatively evolved main-sequence stars and have orbital periods longer than 10 days, these planets are interesting candidates for studies of gas planet evolution, migration, and (potentially) reinflation. Both planets have spent their entire lifetimes near the proposed stellar irradiation threshold at which giant planets become inflated, and neither shows any sign of radius inflation. They probe the regime where inflation begins to become noticeable and are valuable in constraining planet inflation models. In addition, the brightness of the host stars, combined with large atmospheric scale heights of the planets, makes these two systems favorable targets for transit spectroscopy to study their atmospheres and perhaps provide insight into the physical mechanisms that lead to inflated hot Jupiters.

Published
2018

19. A TESS Dress Rehearsal: Planetary Candidates and Variables from K2 Campaign 17

Author

Crossfield, IJM, Crossfield, IJM, Guerrero, N, David, T, Quinn, SN, Feinstein, AD, Huang, C, Yu, L, Collins, KA, Fulton, BJ, Benneke, B, Peterson, M, Bieryla, A, Schlieder, JE, Kosiarek, MR, Bristow, M, Newton, E, Bedell, M, Latham, DW, Christiansen, JL, Esquerdo, GA, Berlind, P, Calkins, ML, Shporer, A, Burt, J, Ballard, S, Rodriguez, JE, Mehrle, N, Dressing, CD, Livingston, JH, Petigura, EA, Seager, S, Dittmann, J, Berardo, D, Sha, L, Essack, Z, Zhan, Z, Owens, M, Kain, I, Isaacson, H, Ciardi, DR, Gonzales, EJ, Howard, AW, Cardoso, JVDM, Crossfield, IJM, Crossfield, IJM, Guerrero, N, David, T, Quinn, SN, Feinstein, AD, Huang, C, Yu, L, Collins, KA, Fulton, BJ, Benneke, B, Peterson, M, Bieryla, A, Schlieder, JE, Kosiarek, MR, Bristow, M, Newton, E, Bedell, M, Latham, DW, Christiansen, JL, Esquerdo, GA, Berlind, P, Calkins, ML, Shporer, A, Burt, J, Ballard, S, Rodriguez, JE, Mehrle, N, Dressing, CD, Livingston, JH, Petigura, EA, Seager, S, Dittmann, J, Berardo, D, Sha, L, Essack, Z, Zhan, Z, Owens, M, Kain, I, Isaacson, H, Ciardi, DR, Gonzales, EJ, Howard, AW, and Cardoso, JVDM

Abstract

We produce light curves for all ∼34,000 targets observed with K2 in Campaign 17 (C17), identifying planet candidates, eclipsing binaries, and other periodic variables. The forward-facing direction of the C17 field means follow-up can begin immediately now that the campaign has concluded and interesting targets have been identified. The C17 field has a large overlap with C6, so this latest campaign also offers an infrequent opportunity to study a large number of targets already observed in a previous K2 campaign. The timing of the C17 data release, shortly before science operations begin with the Transiting Exoplanet Survey Satellite (TESS), also lets us exercise some of the tools and methods developed for identification and dissemination of planet candidates from TESS. We find excellent agreement between these results and those identified using only K2-based tools. Among our planet candidates are several planet candidates with sizes <4 R ⊕ and orbiting stars with Kp ≲ 10 (indicating good RV targets of the sort TESS hopes to find) and a Jupiter-sized single-transit event around a star already hosting a 6 day planet candidate.

Published
2018

20. Revised Stellar Properties of Kepler Targets for the Q1-17 (DR25) Transit Detection Run

Author

Mathur, S, Mathur, S, Huber, D, Batalha, NM, Ciardi, DR, Bastien, FA, Bieryla, A, Buchhave, LA, Cochran, WD, Endl, M, Esquerdo, GA, Furlan, E, Howard, A, Howell, SB, Isaacson, H, Latham, DW, Macqueen, PJ, Silva, DR, Mathur, S, Mathur, S, Huber, D, Batalha, NM, Ciardi, DR, Bastien, FA, Bieryla, A, Buchhave, LA, Cochran, WD, Endl, M, Esquerdo, GA, Furlan, E, Howard, A, Howell, SB, Isaacson, H, Latham, DW, Macqueen, PJ, and Silva, DR

Abstract

The determination of exoplanet properties and occurrence rates using Kepler data critically depends on our knowledge of the fundamental properties (such as temperature, radius, and mass) of the observed stars. We present revised stellar properties for 197,096 Kepler targets observed between Quarters 1-17 (Q1-17), which were used for the final transiting planet search run by the Kepler Mission (Data Release 25, DR25). Similar to the Q1-16 catalog by Huber et al., the classifications are based on conditioning published atmospheric parameters on a grid of Dartmouth isochrones, with significant improvements in the adopted method and over 29,000 new sources for temperatures, surface gravities, or metallicities. In addition to fundamental stellar properties, the new catalog also includes distances and extinctions, and we provide posterior samples for each stellar parameter of each star. Typical uncertainties are ∼27% in radius, ∼17% in mass, and ∼51% in density, which is somewhat smaller than previous catalogs because of the larger number of improved constraints and the inclusion of isochrone weighting when deriving stellar posterior distributions. On average, the catalog includes a significantly larger number of evolved solar-type stars, with an increase of 43.5% in the number of subgiants. We discuss the overall changes of radii and masses of Kepler targets as a function of spectral type, with a particular focus on exoplanet host stars.

Published
2017

21. KELT-14b and KELT-15b: AN INDEPENDENT DISCOVERY of WASP-122b and A NEW HOT JUPITER

Author

Rodriguez, JE, Colón, KD, Stassun, KG, Wright, D, Cargile, PA, Bayliss, D, Pepper, J, Collins, KA, Kuhn, RB, Lund, MB, Siverd, RJ, Zhou, G, Gaudi, BS, Tinney, CG, Penev, K, Tan, TG, Stockdale, C, Curtis, IA, James, D, Udry, S, Segransan, D, Bieryla, A, Latham, DW, Beatty, TG, Eastman, JD, Myers, G, Bartz, J, Bento, J, Jensen, ELN, Oberst, TE, Stevens, DJ, Rodriguez, JE, Colón, KD, Stassun, KG, Wright, D, Cargile, PA, Bayliss, D, Pepper, J, Collins, KA, Kuhn, RB, Lund, MB, Siverd, RJ, Zhou, G, Gaudi, BS, Tinney, CG, Penev, K, Tan, TG, Stockdale, C, Curtis, IA, James, D, Udry, S, Segransan, D, Bieryla, A, Latham, DW, Beatty, TG, Eastman, JD, Myers, G, Bartz, J, Bento, J, Jensen, ELN, Oberst, TE, and Stevens, DJ

Abstract

Gas to Liquids (GTL) diesel has been produced commercially for several years. GTL diesel is known for its excellent properties, including zero aromatics, near zero sulphur and a high cetane number. Most of the GTL diesel produced by commercial plants is utilised as a blend component, especially in blends up to 20%. In these applications, the cold flow properties are potentially less critical, as the cold flow properties of the blend will mostly be determined by the petroleum-derived component. In certain markets, however, it is possible that GTL diesel can be used as a neat diesel, therefore requiring good cold flow properties. An advantage of GTL technology is that the cold flow properties of GTL diesel can be tailored to meet the climatic requirements of a specific geographical area. In the current study, GTL diesel samples with cold flow properties ranging from summer type to winter type and varying intermediate cold flow qualities were evaluated. In line with expectations, it was shown that increasing the degree of isomerisation will improve the cold flow properties of the GTL diesel, whilst the other bulk properties such as density, cetane and viscosity of the fuels are not significantly altered. It is also shown that the excellent cold flow properties of these winter type GTL fuels translate into excellent operability performance.

Published
2016

22. THE KEPLER-454 SYSTEM: A SMALL, NOT-ROCKY INNER PLANET, A JOVIAN WORLD, and A DISTANT COMPANION

Author

Gettel, S, Gettel, S, Charbonneau, D, Dressing, CD, Buchhave, LA, Dumusque, X, Vanderburg, A, Bonomo, AS, Malavolta, L, Pepe, F, Cameron, AC, Latham, DW, Udry, S, Marcy, GW, Isaacson, H, Howard, AW, Davies, GR, Aguirre, VS, Kjeldsen, H, Bedding, TR, Lopez, E, Affer, L, Cosentino, R, Figueira, P, Fiorenzano, AFM, Harutyunyan, A, Johnson, JA, Lopez-Morales, M, Lovis, C, Mayor, M, Micela, G, Molinari, E, Motalebi, F, Phillips, DF, Piotto, G, Queloz, D, Rice, K, Sasselov, D, Ségransan, D, Sozzetti, A, Watson, C, Basu, S, Campante, TL, Christensen-Dalsgaard, J, Kawaler, SD, Metcalfe, TS, Handberg, R, Lund, MN, Lundkvist, MS, Huber, D, Chaplin, WJ, Gettel, S, Gettel, S, Charbonneau, D, Dressing, CD, Buchhave, LA, Dumusque, X, Vanderburg, A, Bonomo, AS, Malavolta, L, Pepe, F, Cameron, AC, Latham, DW, Udry, S, Marcy, GW, Isaacson, H, Howard, AW, Davies, GR, Aguirre, VS, Kjeldsen, H, Bedding, TR, Lopez, E, Affer, L, Cosentino, R, Figueira, P, Fiorenzano, AFM, Harutyunyan, A, Johnson, JA, Lopez-Morales, M, Lovis, C, Mayor, M, Micela, G, Molinari, E, Motalebi, F, Phillips, DF, Piotto, G, Queloz, D, Rice, K, Sasselov, D, Ségransan, D, Sozzetti, A, Watson, C, Basu, S, Campante, TL, Christensen-Dalsgaard, J, Kawaler, SD, Metcalfe, TS, Handberg, R, Lund, MN, Lundkvist, MS, Huber, D, and Chaplin, WJ

Abstract

Kepler-454 (KOI-273) is a relatively bright (V = 11.69 mag), Sun-like star that hosts a transiting planet candidate in a 10.6 day orbit. From spectroscopy, we estimate the stellar temperature to be 5687 ± 50 K, its metallicity to be [m/H] = 0.32 ± 0.08, and the projected rotational velocity to be v sin i < 2.4 km s-1. We combine these values with a study of the asteroseismic frequencies from short cadence Kepler data to estimate the stellar mass to be , the radius to be 1.066 ± 0.012 Ro, and the age to be Gyr. We estimate the radius of the 10.6 day planet as 2.37 ± 0.13 R⊕. Using 63 radial velocity observations obtained with the HARPS-N spectrograph on the Telescopio Nazionale Galileo and 36 observations made with the HIRES spectrograph at the Keck Observatory, we measure the mass of this planet to be 6.8 ± 1.4 M⊕. We also detect two additional non-transiting companions, a planet with a minimum mass of 4.46 ± 0.12 MJ in a nearly circular 524 day orbit and a massive companion with a period >10 years and mass >12.1 MJ. The 12 exoplanets with radii <2.7 R⊕ and precise mass measurements appear to fall into two populations, with those <1.6 R⊕ following an Earth-like composition curve and larger planets requiring a significant fraction of volatiles. With a density of 2.76 ± 0.73 g cm-3, Kepler-454b lies near the mass transition between these two populations and requires the presence of volatiles and/or H/He gas.

Published
2016

24. The spectral impact of magnetic activity on disc-integrated HARPS-N solar observations: Exploring new activity indicators

Author

Thompson, APG, Watson, CA, Haywood, RD, Costes, JC, De Mooij, E, Collier Cameron, A, Dumusque, X, Phillips, DF, Saar, SH, Mortier, A, Milbourne, TW, Aigrain, S, Cegla, HM, Charbonneau, D, Cosentino, R, Ghedina, A, Latham, DW, López-Morales, M, Micela, G, Molinari, E, Poretti, E, Sozzetti, A, Thompson, S, and Walsworth, R

Subjects
planets and satellites: detection, 13. Climate action, Sun: activity, techniques: radial velocities, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Sun: faculae, plages
Abstract

Stellar activity is the major roadblock on the path to finding true Earth-analogue planets with the Doppler technique. Thus, identifying new indicators that better trace magnetic activity (i.e. faculae and spots) is crucial to aid in disentangling these signals from that of a planet’s Doppler wobble. In this work, we investigate activity related features as seen in disc-integrated spectra from the HARPS-N solar telescope. We divide high-activity spectral echelle orders by low-activity master templates (as defined using both $\log {R^{\prime }_{HK}}$ and images from the Solar Dynamics Observatory, SDO), creating ‘relative spectra’. With resolved images of the surface of the Sun (via SDO), the faculae and spot filling factors can be calculated, giving a measure of activity independent of, and in addition to, $\log {R^{\prime }_{HK}}$. We find pseudo-emission (and pseudo-absorption) features in the relative spectra that are similar to those reported in our previous work on α Cen B. In α Cen B, the features are shown to correlate better to changes in faculae filling factor than spot filling factor. In this work, we more confidently identify changes in faculae coverage of the visible hemisphere of the Sun as the source of features produced in the relative spectra. Finally, we produce trailed spectra to observe the radial velocity component of the features, which show that the features move in a redward direction as one would expect when tracking active regions rotating on the surface of a star.

25. An ultrahot Neptune in the Neptune desert

Author

Jenkins, JS, Díaz, MR, Kurtovic, NT, Espinoza, N, Vines, JI, Rojas, PAP, Brahm, R, Torres, P, Cortés-Zuleta, P, Soto, MG, Lopez, ED, King, GW, Wheatley, PJ, Winn, JN, Ciardi, DR, Ricker, G, Vanderspek, R, Latham, DW, Seager, S, Jenkins, JM, Beichman, CA, Bieryla, A, Burke, CJ, Christiansen, JL, Henze, CE, Klaus, TC, McCauliff, S, Mori, M, Narita, N, Nishiumi, T, Tamura, M, De Leon, JP, Quinn, SN, Villaseñor, JN, Vezie, M, Lissauer, JJ, Collins, KA, Collins, KI, Isopi, G, Mallia, F, Ercolino, A, Petrovich, C, Jordán, A, Acton, JS, Armstrong, DJ, Bayliss, D, Bouchy, F, Belardi, C, Bryant, EM, Burleigh, MR, Cabrera, J, Casewell, SL, Chaushev, A, Cooke, BF, Eigmüller, P, Erikson, A, Foxell, E, Gänsicke, BT, Gill, S, Gillen, E, Günther, MN, Goad, MR, Hooton, MJ, Jackman, JAG, Louden, T, McCormac, J, Moyano, M, Nielsen, LD, Pollacco, D, Queloz, D, Rauer, H, Raynard, L, Smith, AMS, Tilbrook, RH, Titz-Weider, R, Turner, O, Udry, S, Walker, Watson, CA, West, RG, Palle, E, Ziegler, C, Law, N, and Mann, AW

Subjects
astro-ph.SR, 13. Climate action, astro-ph.EP, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics
Abstract

About one out of 200 Sun-like stars has a planet with an orbital period shorter than one day: an ultra-short-period planet (Sanchis-ojeda et al. 2014; Winn et al. 2018). All of the previously known ultra-short-period planets are either hot Jupiters, with sizes above 10 Earth radii (Re), or apparently rocky planets smaller than 2 Re. Such lack of planets of intermediate size (the "hot Neptune desert") has been interpreted as the inability of low-mass planets to retain any hydrogen/helium (H/He) envelope in the face of strong stellar irradiation. Here, we report the discovery of an ultra-short-period planet with a radius of 4.6 Re and a mass of 29 Me, firmly in the hot Neptune desert. Data from the Transiting Exoplanet Survey Satellite (Ricker et al. 2015) revealed transits of the bright Sun-like star \starname\, every 0.79 days. The planet's mean density is similar to that of Neptune, and according to thermal evolution models, it has a H/He-rich envelope constituting 9.0^(+2.7)_(-2.9)% of the total mass. With an equilibrium temperature around 2000 K, it is unclear how this "ultra-hot Neptune" managed to retain such an envelope. Follow-up observations of the planet's atmosphere to better understand its origin and physical nature will be facilitated by the star's brightness (Vmag=9.8).

26. An unusually low density ultra-short period super-Earth and three mini-Neptunes around the old star TOI-561

Author

Lacedelli, G, Malavolta, L, Borsato, L, Piotto, G, Nardiello, D, Mortier, A, Stalport, M, Collier Cameron, A, Poretti, E, Buchhave, LA, López-Morales, M, Nascimbeni, V, Wilson, TG, Udry, S, Latham, DW, Bonomo, AS, Damasso, M, Dumusque, X, Jenkins, JM, Lovis, C, Rice, K, Sasselov, D, Winn, JN, Andreuzzi, G, Cosentino, R, Charbonneau, D, Di Fabrizio, L, Martnez Fiorenzano, AF, Ghedina, A, Harutyunyan, A, Lienhard, F, Micela, G, Molinari, E, Pagano, I, Pepe, F, Phillips, DF, Pinamonti, M, Ricker, G, Scandariato, G, Sozzetti, A, and Watson, CA

Subjects
techniques: photometric, planets and satellites: detection, stars: individual: TOI-561 (TIC 377064495, Gaia DR2 3850421005290172416), 13. Climate action, techniques: radial velocities, planets and satellites: composition
Abstract

Based on HARPS-N radial velocities (RVs) and TESS photometry, we present a full characterisation of the planetary system orbiting the late G dwarf TOI-561. After the identification of three transiting candidates by TESS, we discovered two additional external planets from RV analysis. RVs cannot confirm the outer TESS transiting candidate, which would also make the system dynamically unstable. We demonstrate that the two transits initially associated with this candidate are instead due to single transits of the two planets discovered using RVs. The four planets orbiting TOI-561 include an ultra-short period (USP) super-Earth (TOI-561 b) with period $P_{\rm b} = 0.45$ d, mass $M_{\rm b} =1.59 \pm 0.36$ M$_\oplus$ and radius $R_{\rm b}=1.42 \pm 0.07$ R$_\oplus$, and three mini-Neptunes: TOI-561 c, with $P_{\rm c} = 10.78$ d, $M_{\rm c} = 5.40 \pm 0.98$ M$_\oplus$, $R_{\rm c}= 2.88 \pm 0.09$ R$_\oplus$; TOI-561 d, with $P_{\rm d} = 25.6$ d, $M_{\rm d} = 11.9 \pm 1.3$ M$_\oplus$, $R_{\rm d} = 2.53 \pm 0.13$ R$_\oplus$; and TOI-561 e, with $P_{\rm e} = 77.2$ d, $M_{\rm e} = 16.0 \pm 2.3$ M$_\oplus$, $R_{\rm e} = 2.67 \pm 0.11$ R$_\oplus$. Having a density of $3.0 \pm 0.8$ g cm$^{-3}$, TOI-561 b is the lowest density USP planet known to date. Our N-body simulations confirm the stability of the system and predict a strong, anti-correlated, long-term transit time variation signal between planets d and e. The unusual density of the inner super-Earth and the dynamical interactions between the outer planets make TOI-561 an interesting follow-up target.

27. Detection Limits of Low-mass, Long-period Exoplanets Using Gaussian Processes Applied to HARPS-N Solar Radial Velocities

Author

Langellier, N, Milbourne, TW, Phillips, DF, Haywood, RD, Saar, SH, Mortier, A, Malavolta, L, Thompson, S, Cameron, AC, Dumusque, X, Cegla, HM, Latham, DW, Maldonado, J, Watson, CA, Buchschacher, N, Cecconi, M, Charbonneau, D, Cosentino, R, Ghedina, A, Gonzalez, M, Li, CH, Lodi, M, López-Morales, M, Micela, G, Molinari, E, Pepe, F, Poretti, E, Rice, K, Sasselov, D, Sozzetti, A, Udry, S, and Walsworth, RL

Subjects
astro-ph.SR, 13. Climate action, astro-ph.EP, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics::Galaxy Astrophysics, astro-ph.IM
Abstract

Radial velocity (RV) searches for Earth-mass exoplanets in the habitable zone around Sun-like stars are limited by the effects of stellar variability on the host star. In particular, suppression of convective blueshift and brightness inhomogeneities due to photospheric faculae/plage and starspots are the dominant contribution to the variability of such stellar RVs. Gaussian process (GP) regression is a powerful tool for statistically modeling these quasi-periodic variations. We investigate the limits of this technique using 800 days of RVs from the solar telescope on the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) spectrograph. These data provide a well-sampled time series of stellar RV variations. Into this data set, we inject Keplerian signals with periods between 100 and 500 days and amplitudes between 0.6 and 2.4 m s$^{-1}$. We use GP regression to fit the resulting RVs and determine the statistical significance of recovered periods and amplitudes. We then generate synthetic RVs with the same covariance properties as the solar data to determine a lower bound on the observational baseline necessary to detect low-mass planets in Venus-like orbits around a Sun-like star. Our simulations show that discovering planets with a larger mass ($\sim$ 0.5 m s$^{-1}$) using current-generation spectrographs and GP regression will require more than 12 yr of densely sampled RV observations. Furthermore, even with a perfect model of stellar variability, discovering a true exo-Venus ($\sim$ 0.1 m s$^{-1}$) with current instruments would take over 15 yr. Therefore, next-generation spectrographs and better models of stellar variability are required for detection of such planets.

28. K2-111: An old system with two planets in near-resonance

Author

Mortier, A, Zapatero Osorio, MR, Malavolta, L, Alibert, Y, Rice, K, Lillo-Box, J, Vanderburg, A, Oshagh, M, Buchhave, L, Adibekyan, V, Delgado Mena, E, Lopez-Morales, M, Charbonneau, D, Sousa, SG, Lovis, C, Affer, L, Allende Prieto, C, Barros, SCC, Benatti, S, Bonomo, AS, Boschin, W, Bouchy, F, Cabral, A, Collier Cameron, A, Cosentino, R, Cristiani, S, Demangeon, ODS, Di Marcantonio, P, D'Odorico, V, Dumusque, X, Ehrenreich, D, Figueira, P, Fiorenzano, A, Ghedina, A, González Hernández, JI, Haldemann, J, Harutyunyan, A, Haywood, RD, Latham, DW, Lavie, B, Lo Curto, G, Maldonado, J, Manescau, A, Martins, CJAP, Mayor, M, Mégevand, D, Mehner, A, Micela, G, Molaro, P, Molinari, E, Nunes, NJ, Pepe, FA, Palle, E, Phillips, D, Piotto, G, Pinamonti, M, Poretti, E, Riva, M, Rebolo, R, Santos, NC, Sasselov, D, Sozzetti, A, Suárez Mascareño, A, Udry, S, West, RG, Watson, CA, and Wilson, TG

Subjects
techniques: photometric, planets and satellites: detection, 13. Climate action, techniques: radial velocities, stars: individual (K2-111), techniques: spectroscopic
Abstract

This paper reports on the detailed characterisation of the K2-111 planetary system with K2, WASP, and ASAS-SN photometry as well as high-resolution spectroscopic data from HARPS-N and ESPRESSO. The host, K2-111, is confirmed to be a mildly evolved ($\log g=4.17$), iron-poor ([Fe/H]$=-0.46$), but alpha-enhanced ([$\alpha$/Fe]$=0.27$), chromospherically quiet, very old thick disc G2 star. A global fit, performed by using PyORBIT shows that the transiting planet, K2-111b, orbits with a period $P_b=5.3518\pm0.0004$ d, and has a planet radius of $1.82^{+0.11}_{-0.09}$ R$_\oplus$ and a mass of $5.29^{+0.76}_{-0.77}$ M$_\oplus$, resulting in a bulk density slightly lower than that of the Earth. The stellar chemical composition and the planet properties are consistent with K2-111b being a terrestrial planet with an iron core mass fraction lower than the Earth. We announce the existence of a second signal in the radial velocity data that we attribute to a non-transiting planet, K2-111c, with an orbital period of $15.6785\pm 0.0064$ days, orbiting in near-3:1 mean-motion resonance with the transiting planet, and a minimum planet mass of $11.3\pm1.1$ M$_\oplus$. Both planet signals are independently detected in the HARPS-N and ESPRESSO data when fitted separately. There are potentially more planets in this resonant system, but more well-sampled data are required to confirm their presence and physical parameters.

29. The Kepler-19 System: A Thick-envelope Super-Earth with Two Neptune-mass Companions Characterized Using Radial Velocities and Transit Timing Variations

Author

Malavolta, L, Borsato, L, Granata, V, Piotto, G, Lopez, E, Vanderburg, A, Figueira, P, Mortier, A, Nascimbeni, V, Affer, L, Bonomo, AS, Bouchy, F, Buchhave, LA, Charbonneau, D, Cameron, AC, Cosentino, R, Dressing, CD, Dumusque, X, Fiorenzano, AFM, Harutyunyan, A, Haywood, RD, Johnson, JA, Latham, DW, Lopez-Morales, M, Lovis, C, Mayor, M, Micela, G, Molinari, E, Motalebi, F, Pepe, F, Phillips, DF, Pollacco, D, Queloz, D, Rice, K, Sasselov, D, Ségransan, D, Sozzetti, A, Udry, S, and Watson, C

Subjects
techniques: photometric, planets and satellites: dynamical evolution and stability, stars: individual (Kepler-19), 13. Climate action, techniques: radial velocities, planets and satellites: composition, planetary systems
Abstract

We report a detailed characterization of the Kepler-19 system. This star was previously known to host a transiting planet with a period of 9.29 days, a radius of 2.2 R⊕ and an upper limit on the mass of 20 M⊕. The presence of a second, non-transiting planet was inferred from the transit time variations (TTVs) of Kepler-19b, over 8 quarters of Kepler photometry, although neither mass nor period could be determined. By combining new TTVs measurements from all the Kepler quarters and 91 high-precision radial velocities obtained with the HARPS-N spectrograph, we measured through dynamical simulations a mass of 8.4±1.6 M⊕ for Kepler-19b. From the same data, assuming system coplanarity, we determined an orbital period of 28.7 days and a mass of 13.1±2.7 M⊕ for Kepler-19c and discovered a Neptune-like planet with a mass of 20.3±3.4 M⊕ on a 63 days orbit. By comparing dynamical simulations with non-interacting Keplerian orbits, we concluded that neglecting interactions between planets may lead to systematic errors that could hamper the precision in the orbital parameters when the dataset spans several years. With a density of 4.32±0.87 g cm−3 (0.78±0.16 ρ⊕) Kepler-19b belongs to the group of planets with a rocky core and a significant fraction of volatiles, in opposition to low-density planets characterized by transit-time variations only and the increasing number of rocky planets with Earth-like density. Kepler-19 joins the small number of systems that reconcile transit timing variation and radial velocity measurements., The HARPS-N project was funded by the Prodex Program of the Swiss Space Office (SSO), the Harvard University Origin of Life Initiative (HUOLI), the Scottish Universities Physics Alliance (SUPA), the University of Geneva, the Smithsonian Astrophysical Observatory (SAO), the Italian National Astrophysical Institute (INAF), University of St. Andrews, Queen’s University Belfast, and University of Edinburgh. The research leading to these results received funding from the European Union Seventh Framework Programme (FP7/2007- 2013) under grant agreement number 313014 (ETAEARTH). This work was performed in part under contract with the California Institute of Technology/Jet Propulsion Laboratory funded by NASA through the Sagan Fellowship Program executed by the NASA Exoplanet Science Institute. A.V. is supported by the NSF Graduate Research Fellowship, grant No. DGE 1144152. This publication was made possible 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. This material is based upon work supported by NASA under grant No. NNX15AC90G issued through the Exoplanets Research Program. P.F. acknowledges support by Fundação para a Ciência e a Tecnologia (FCT) through Investigador FCT contract of reference IF/01037/2013 and POPH/FSE (EC) by FEDER funding through the program “Programa Operacional de Factores de Competitividade—COMPETE”, and further support in the form of an exploratory project of reference IF/ 01037/2013CP1191/CT0001. X.D. is grateful to the Society in Science–Branco Weiss Fellowship for its financial support.

30. Mid-to-late M Dwarfs Lack Jupiter Analogs

Author

Pass, Emily K, Winters, Jennifer G, Charbonneau, David, Irwin, Jonathan M, Latham, David W, Berlind, Perry, Calkins, Michael L, Esquerdo, Gilbert A, Mink, Jessica, Pass, EK [0000-0002-1533-9029], Winters, JG [0000-0001-6031-9513], Charbonneau, D [0000-0002-9003-484X], Latham, DW [0000-0001-9911-7388], Calkins, ML [0000-0002-2830-5661], Esquerdo, GA [0000-0002-9789-5474], Mink, J [0000-0003-3594-1823], and Apollo - University of Cambridge Repository

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), Astrophysics - Solar and Stellar Astrophysics, 5101 Astronomical Sciences, FOS: Physical sciences, 5109 Space Sciences, 51 Physical Sciences, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics - Earth and Planetary Astrophysics
Abstract

Cold Jovian planets play an important role in sculpting the dynamical environment in which inner terrestrial planets form. The core accretion model predicts that giant planets cannot form around low-mass M dwarfs, although this idea has been challenged by recent planet discoveries. Here, we investigate the occurrence rate of giant planets around low-mass (0.1-0.3M$_\odot$) M dwarfs. We monitor a volume-complete, inactive sample of 200 such stars located within 15 parsecs, collecting four high-resolution spectra of each M dwarf over six years and performing intensive follow-up monitoring of two candidate radial-velocity variables. We use TRES on the 1.5 m telescope at the Fred Lawrence Whipple Observatory and CHIRON on the Cerro Tololo Inter-American Observatory 1.5 m telescope for our primary campaign, and MAROON-X on Gemini North for high-precision follow-up. We place a 95%-confidence upper limit of 1.5% (68%-confidence limit of 0.57%) on the occurrence of $M_{\rm P}$sin$i > $1M$_{\rm J}$ giant planets out to the water snow line and provide additional constraints on the giant planet population as a function of $M_{\rm P}$sin$i$ and period. Beyond the snow line ($100$ K $< T_{\rm eq} < 150$ K), we place 95%-confidence upper limits of 1.5%, 1.7%, and 4.4% (68%-confidence limits of 0.58%, 0.66%, and 1.7%) for 3M$_{\rm J} < M_{\rm P}$sin$i < 10$M$_{\rm J}$, 0.8M$_{\rm J} < M_{\rm P}$sin$i < 3$M$_{\rm J}$, and 0.3M$_{\rm J} < M_{\rm P}$sin$i < 0.8$M$_{\rm J}$ giant planets; i.e., Jupiter analogs are rare around low-mass M dwarfs. In contrast, surveys of Sun-like stars have found that their giant planets are most common at these Jupiter-like instellations., Accepted for publication in AJ; 19 pages, 5 figures, 2 tables

Published
2023

31. TOI-4010: A System of Three Large Short-Period Planets With a Massive Long-Period Companion

Author

Kunimoto, Michelle, Vanderburg, Andrew, Huang, Chelsea X., Davis, M. Ryleigh, Affer, Laura, Cameron, Andrew Collier, Charbonneau, David, Cosentino, Rosario, Damasso, Mario, Dumusque, Xavier, Fiorenzano, A. F. Martnez, Ghedina, Adriano, Haywood, R. D., Lienhard, Florian, López-Morales, Mercedes, Mayor, Michel, Pepe, Francesco, Pinamonti, Matteo, Poretti, Ennio, Maldonado, Jesús, Rice, Ken, Sozzetti, Alessandro, Wilson, Thomas G., Udry, Stéphane, Baptista, Jay, Barkaoui, Khalid, Becker, Juliette, Benni, Paul, Bieryla, Allyson, Bosch-Cabot, Pau, Ciardi, David R., Collins, Karen A., Collins, Kevin I., Evans, Elise, Dupuy, Trent J., Goliguzova, Maria V., Guerra, Pere, Kraus, Adam, Lissauer, Jack J., Huber, Daniel, Murgas, Felipe, Palle, Enric, Quinn, Samuel N., Safonov, Boris S., Schwarz, Richard P., Shporer, Avi, Stassun, Keivan G., Jenkins, Jon M., Latham, David W., Ricker, George R., Seager, Sara, Vanderspek, Roland, Winn, Joshua, Essack, Zahra, Lewis, Hannah M., Rose, Mark E., Kunimoto, M [0000-0001-9269-8060], Vanderburg, A [0000-0001-7246-5438], Huang, CX [0000-0003-0918-7484], Davis, MR [0000-0002-7451-4704], Affer, L [0000-0001-5600-3778], Cameron, AC [0000-0002-8863-7828], Charbonneau, D [0000-0002-9003-484X], Cosentino, R [0000-0003-1784-1431], Damasso, M [0000-0001-9984-4278], Dumusque, X [0000-0002-9332-2011], Fiorenzano, AFM [0000-0002-4272-4272], Ghedina, A [0000-0003-4702-5152], Haywood, RD [0000-0001-9140-3574], Lienhard, F [0000-0003-4047-0771], López-Morales, M [0000-0003-3204-8183], Mayor, M [0000-0002-9352-5935], Pepe, F [0000-0002-9815-773X], Pinamonti, M [0000-0002-4445-1845], Poretti, E [0000-0003-1200-0473], Maldonado, J [0000-0002-2218-5689], Rice, K [0000-0002-6379-9185], Sozzetti, A [0000-0002-7504-365X], Wilson, TG [0000-0001-8749-1962], Udry, S [0000-0001-7576-6236], Baptista, J [0000-0002-9306-1704], Barkaoui, K [0000-0003-1464-9276], Becker, J [0000-0002-7733-4522], Benni, P [0000-0001-6981-8722], Bieryla, A [0000-0001-6637-5401], Bosch-Cabot, P [0000-0002-1514-5558], Ciardi, DR [0000-0002-5741-3047], Collins, KA [0000-0001-6588-9574], Collins, KI [0000-0003-2781-3207], Dupuy, TJ [0000-0001-9823-1445], Goliguzova, MV [0000-0003-2228-7914], Guerra, P [0000-0002-4308-2339], Kraus, A [0000-0001-9811-568X], Lissauer, JJ [0000-0001-6513-1659], Huber, D [0000-0001-8832-4488], Murgas, F [0000-0001-9087-1245], Palle, E [0000-0003-0987-1593], Quinn, SN [0000-0002-8964-8377], Safonov, BS [0000-0003-1713-3208], Schwarz, RP [0000-0001-8227-1020], Shporer, A [0000-0002-1836-3120], Stassun, KG [0000-0002-3481-9052], Jenkins, JM [0000-0002-4715-9460], Latham, DW [0000-0001-9911-7388], Ricker, GR [0000-0003-2058-6662], Seager, S [0000-0002-6892-6948], Vanderspek, R [0000-0001-6763-6562], Winn, J [0000-0002-4265-047X], Essack, Z [0000-0002-2482-0180], Lewis, HM [0000-0002-7871-085X], Rose, ME [0000-0003-4724-745X], Apollo - University of Cambridge Repository, 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
MCC, Earth and Planetary Astrophysics (astro-ph.EP), Exoplanets, Exoplanet dynamics, FOS: Physical sciences, DAS, 5109 Space Sciences, Hot Neptunes, QB Astronomy, Transit photometry, Exoplanet systems, 51 Physical Sciences, Astrophysics - Earth and Planetary Astrophysics, QB
Abstract

We report the confirmation of three exoplanets transiting TOI-4010 (TIC-352682207), a metal-rich K dwarf observed by TESS in Sectors 24, 25, 52, and 58. We confirm these planets with HARPS-N radial velocity observations and measure their masses with 8 - 12% precision. TOI-4010 b is a sub-Neptune ($P = 1.3$ days, $R_{p} = 3.02_{-0.08}^{+0.08}~R_{\oplus}$, $M_{p} = 11.00_{-1.27}^{+1.29}~M_{\oplus}$) in the hot Neptune desert, and is one of the few such planets with known companions. Meanwhile, TOI-4010 c ($P = 5.4$ days, $R_{p} = 5.93_{-0.12}^{+0.11}~R_{\oplus}$, $M_{p} = 20.31_{-2.11}^{+2.13}~M_{\oplus}$) and TOI-4010 d ($P = 14.7$ days, $R_{p} = 6.18_{-0.14}^{+0.15}~R_{\oplus}$, $M_{p} = 38.15_{-3.22}^{+3.27}~M_{\oplus}$) are similarly-sized sub-Saturns on short-period orbits. Radial velocity observations also reveal a super-Jupiter-mass companion called TOI-4010 e in a long-period, eccentric orbit ($P \sim 762$ days and $e \sim 0.26$ based on available observations). TOI-4010 is one of the few systems with multiple short-period sub-Saturns to be discovered so far., Comment: 26 pages, 16 figures, published in AJ; (v3) added missing citation

Published
2023
Full Text
View/download PDF

32. K2-79b and K2-222b: Mass Measurements of Two Small Exoplanets with Periods beyond 10 days that Overlap with Periodic Magnetic Activity Signals

Author

Chantanelle Nava, Mercedes López-Morales, Annelies Mortier, Li Zeng, Helen A. C. Giles, Allyson Bieryla, Andrew Vanderburg, Lars A. Buchhave, Ennio Poretti, Steven H. Saar, Xavier Dumusque, David W. Latham, David Charbonneau, Mario Damasso, Aldo S. Bonomo, Christophe Lovis, Andrew Collier Cameron, Jason D. Eastman, Alessandro Sozzetti, Rosario Cosentino, Marco Pedani, Francesco Pepe, Emilio Molinari, Dimitar Sasselov, Michel Mayor, Manu Stalport, Luca Malavolta, Ken Rice, Christopher A. Watson, A. F. Martinez Fiorenzano, Luca Di Fabrizio, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Nava, Chantanelle [0000-0001-8838-3883], López-Morales, Mercedes [0000-0003-3204-8183], Mortier, Annelies [0000-0001-7254-4363], Zeng, Li [0000-0003-1957-6635], Giles, Helen AC [0000-0001-6777-4797], Bieryla, Allyson [0000-0001-6637-5401], Vanderburg, Andrew [0000-0001-7246-5438], Buchhave, Lars A [0000-0003-1605-5666], Poretti, Ennio [0000-0003-1200-0473], Saar, Steven H [0000-0001-7032-8480], Dumusque, Xavier [0000-0002-9332-2011], Latham, David W [0000-0001-9911-7388], Charbonneau, David [0000-0002-9003-484X], Damasso, Mario [0000-0001-9984-4278], Bonomo, Aldo S [0000-0002-6177-198X], Eastman, Jason D [0000-0003-3773-5142], Sozzetti, Alessandro [0000-0002-7504-365X], Pedani, Marco [0000-0002-5752-6260], Molinari, Emilio [0000-0002-1742-7735], Sasselov, Dimitar [0000-0001-7014-1771], Mayor, Michel [0000-0002-9352-5935], Malavolta, Luca [0000-0002-6492-2085], Martinez Fiorenzano, AF [0000-0002-4272-4272], Apollo - University of Cambridge Repository, Nava, C [0000-0001-8838-3883], López-Morales, M [0000-0003-3204-8183], Mortier, A [0000-0001-7254-4363], Zeng, L [0000-0003-1957-6635], Giles, HAC [0000-0001-6777-4797], Bieryla, A [0000-0001-6637-5401], Vanderburg, A [0000-0001-7246-5438], Buchhave, LA [0000-0003-1605-5666], Poretti, E [0000-0003-1200-0473], Saar, SH [0000-0001-7032-8480], Dumusque, X [0000-0002-9332-2011], Latham, DW [0000-0001-9911-7388], Charbonneau, D [0000-0002-9003-484X], Damasso, M [0000-0001-9984-4278], Bonomo, AS [0000-0002-6177-198X], Eastman, JD [0000-0003-3773-5142], Sozzetti, A [0000-0002-7504-365X], Pedani, M [0000-0002-5752-6260], Molinari, E [0000-0002-1742-7735], Sasselov, D [0000-0001-7014-1771], Mayor, M [0000-0002-9352-5935], and Malavolta, L [0000-0002-6492-2085]

Subjects
MCC, Earth and Planetary Astrophysics (astro-ph.EP), The Solar System, Exoplanets, and Astrobiology, Exoplanet astronomy, FOS: Physical sciences, Astronomy and Astrophysics, 3rd-DAS, Stellar activity, QC Physics, Space and Planetary Science, astro-ph.EP, QB Astronomy, QC, Astrophysics - Earth and Planetary Astrophysics, QB
Abstract

We present mass and radius measurements of K2-79b and K2-222b, two transiting exoplanets orbiting active G-type stars. Their respective 10.99d and 15.39d orbital periods fall near periods of signals induced by stellar magnetic activity. The two signals might therefore interfere and lead to an inaccurate estimate of exoplanet mass. We present a method to mitigate these effects when radial velocity and activity indicator observations are available over multiple observing seasons and the orbital period of the exoplanet is known. We perform correlation and periodogram analyses on sub-sets composed of each target's two observing seasons, in addition to the full data sets. For both targets, these analyses reveal an optimal season with little to no interference at the orbital period of the known exoplanet. We make a confident mass detection of each exoplanet by confirming agreement between fits to the full radial velocity set and the optimal season. For K2-79b, we measure a mass of 11.8 $\pm$ 3.6 $M_{Earth}$ and a radius of 4.09 $\pm$ 0.17 $R_{Earth}$. For K2-222b, we measure a mass of 8.0 $\pm$ 1.8 $M_{Earth}$ and a radius of 2.35 $\pm$ 0.08 $R_{Earth}$. According to model predictions, K2-79b is a highly irradiated Uranus-analog and K2-222b hosts significant amounts of water ice. We also present an RV solution for a candidate second companion orbiting K2-222 at 147.5d., Comment: 33 pages, 17 figures, 13 tables

Published
2022
Full Text
View/download PDF

33. TESS Eclipsing Binary Stars. I. Short-cadence Observations of 4584 Eclipsing Binaries in Sectors 1-26

Author

Andrej Prša, Angela Kochoska, Kyle E. Conroy, Nora Eisner, Daniel R. Hey, Luc IJspeert, Ethan Kruse, Scott W. Fleming, Cole Johnston, Martti H. Kristiansen, Daryll LaCourse, Danielle Mortensen, Joshua Pepper, Keivan G. Stassun, Guillermo Torres, Michael Abdul-Masih, Joheen Chakraborty, Robert Gagliano, Zhao Guo, Kelly Hambleton, Kyeongsoo Hong, Thomas Jacobs, David Jones, Veselin Kostov, Jae Woo Lee, Mark Omohundro, Jerome A. Orosz, Emma J. Page, Brian P. Powell, Saul Rappaport, Phill Reed, Jeremy Schnittman, Hans Martin Schwengeler, Avi Shporer, Ivan A. Terentev, Andrew Vanderburg, William F. Welsh, Douglas A. Caldwell, John P. Doty, Jon M. Jenkins, David W. Latham, George R. Ricker, Sara Seager, Joshua E. Schlieder, Bernie Shiao, Roland Vanderspek, Joshua N. Winn, Prša, A [0000-0002-1913-0281], Kochoska, A [0000-0002-9739-8371], Conroy, KE [0000-0002-5442-8550], Eisner, N [0000-0002-9138-9028], Hey, DR [0000-0003-3244-5357], Kruse, E [0000-0002-0493-1342], Fleming, SW [0000-0003-0556-027X], Kristiansen, MH [0000-0002-2607-138X], Lacourse, D [0000-0002-8527-2114], Pepper, J [0000-0002-3827-8417], Stassun, KG [0000-0002-3481-9052], Torres, G [0000-0002-5286-0251], Abdul-Masih, M [0000-0001-6566-7568], Guo, Z [0000-0002-0951-2171], Hambleton, K [0000-0001-5473-856X], Hong, K [0000-0002-8692-2588], Jacobs, T [0000-0003-3988-3245], Jones, D [0000-0001-9786-1031], Kostov, V [0000-0001-9786-1031], Lee, JW [0000-0002-5739-9804], Orosz, JA [0000-0001-9647-2886], Powell, BP [0000-0003-0501-2636], Rappaport, S [0000-0003-3182-5569], Reed, P [0000-0002-5005-1215], Schwengeler, HM [0000-0002-1637-2189], Shporer, A [0000-0002-1836-3120], Vanderburg, A [0000-0001-7246-5438], Welsh, WF [0000-0003-2381-5301], Caldwell, DA [0000-0003-1963-9616], Doty, JP [0000-0003-2996-8421], Jenkins, JM [0000-0002-4715-9460], Latham, DW [0000-0001-9911-7388], Ricker, GR [0000-0003-2058-6662], Schlieder, JE [0000-0001-5347-7062], Vanderspek, R [0000-0001-6763-6562], Winn, JN [0000-0002-4265-047X], and Apollo - University of Cambridge Repository

Subjects
Astronomy, EXTREME AMPLITUDE, PULSATING STARS, FOS: Physical sciences, PLANET, Fundamental parameters of stars, Astronomy & Astrophysics, Light curves, Sky surveys, VARIABLE OBJECTS, Photometry, FULL FRAME IMAGES, Eclipsing binary stars, SUBDWARF B STARS, GALAXY ZOO, HEARTBEAT STAR, Solar and Stellar Astrophysics (astro-ph.SR), Science & Technology, ERROR-CORRECTION, Astronomy and Astrophysics, CATALOG, Astrophysics - Solar and Stellar Astrophysics, 5101 Astronomical Sciences, Space and Planetary Science, Physical Sciences, Catalogs, 51 Physical Sciences
Abstract

In this paper we present a catalog of 4584 eclipsing binaries observed during the first two years (26 sectors) of the TESS survey. We discuss selection criteria for eclipsing binary candidates, detection of hither-to unknown eclipsing systems, determination of the ephemerides, the validation and triage process, and the derivation of heuristic estimates for the ephemerides. Instead of keeping to the widely used discrete classes, we propose a binary star morphology classification based on a dimensionality reduction algorithm. Finally, we present statistical properties of the sample, we qualitatively estimate completeness, and discuss the results. The work presented here is organized and performed within the TESS Eclipsing Binary Working Group, an open group of professional and citizen scientists; we conclude by describing ongoing work and future goals for the group. The catalog is available from http://tessEBs.villanova.edu and from MAST., 32 pages, 21 figures, accepted to ApJ Supplement Series; comments welcome

Published
2022

34. Complex Modulation of Rapidly Rotating Young M Dwarfs:Adding Pieces to the Puzzle

Author

Günther, Maximilian N., Berardo, David A., Ducrot, Elsa, Murray, Catriona A., Stassun, Keivan G., Olah, Katalin, Bouma, L. G., Rappaport, Saul, Winn, Joshua N., Feinstein, Adina D., Matthews, Elisabeth C., Sebastian, Daniel, Rackham, Benjamin V., Seli, Bálint, J. Triaud, Amaury H. M., Gillen, Edward, Levine, Alan M., Demory, Brice-Olivier, Gillon, Michaël, Queloz, Didier, Ricker, George R., Vanderspek, Roland K., Seager, Sara, Latham, David W., Jenkins, Jon M., Brasseur, C. E., Colón, Knicole D., Daylan, Tansu, Delrez, Laetitia, Fausnaugh, Michael, Garcia, Lionel J., Jayaraman, Rahul, Jehin, Emmanuel, Kristiansen, Martti H., Kruijssen, J. M. Diederik, Pedersen, Peter Pihlmann, Pozuelos, Francisco J., Rodriguez, Joseph E., Wohler, Bill, Zhan, Zhuchang, Günther, MN [0000-0002-3164-9086], Berardo, DA [0000-0001-6298-412X], Ducrot, E [0000-0002-7008-6888], Murray, CA [0000-0001-8504-5862], Stassun, KG [0000-0002-3481-9052], Olah, K [0000-0003-3669-7201], Bouma, LG [0000-0002-0514-5538], Rappaport, S [0000-0003-3182-5569], Winn, JN [0000-0002-4265-047X], Feinstein, AD [0000-0002-9464-8101], Matthews, EC [0000-0003-0593-1560], Sebastian, D [0000-0002-2214-9258], Rackham, BV [0000-0002-3627-1676], Seli, B [0000-0002-3658-2175], Amaury, AHM [0000-0002-5510-8751], Gillen, E [0000-0003-2851-3070], Levine, AM [0000-0001-8172-0453], Demory, BO [0000-0002-9355-5165], Gillon, M [0000-0003-1462-7739], Queloz, D [0000-0002-3012-0316], Ricker, GR [0000-0003-2058-6662], Vanderspek, RK [0000-0001-6763-6562], Seager, S [0000-0002-6892-6948], Latham, DW [0000-0001-9911-7388], Jenkins, JM [0000-0002-4715-9460], Brasseur, CE [0000-0002-9314-960X], Colón, KD [0000-0001-8020-7121], Daylan, T [0000-0002-6939-9211], Delrez, L [0000-0001-6108-4808], Fausnaugh, M [0000-0002-9113-7162], Garcia, LJ [0000-0002-4296-2246], Jayaraman, R [0000-0002-7778-3117], Jehin, E [0000-0001-8923-488X], Kristiansen, MH [0000-0002-2607-138X], Kruijssen, JMD [0000-0002-8804-0212], Pedersen, PP [0000-0002-5220-609X], Pozuelos, FJ [0000-0003-1572-7707], Rodriguez, JE [0000-0001-8812-0565], Wohler, B [0000-0002-5402-9613], Zhan, Z [0000-0002-4142-1800], and Apollo - University of Cambridge Repository

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), astro-ph.SR, Variable stars, 520 Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Stellar flares, Astrophysics::Cosmology and Extragalactic Astrophysics, M dwarf stars, Starspots, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, astro-ph.EP, Periodic variable stars, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, T Tauri stars, Stellar rotation, Pre-main sequence stars, Solar and Stellar Astrophysics (astro-ph.SR), Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics, Stellar activity
Abstract

New sets of young M dwarfs with complex, sharp-peaked, and strictly periodic photometric modulations have recently been discovered with Kepler/K2 (scallop shells) and TESS (complex rotators). All are part of star-forming associations, are distinct from other variable stars, and likely belong to a unified class. Suggested hypotheses include star spots, accreting dust disks, co-rotating clouds of material, magnetically constrained material, spots and misaligned disks, and pulsations. Here, we provide a comprehensive overview and add new observational constraints with TESS and SPECULOOS Southern Observatory (SSO) photometry. We scrutinize all hypotheses from three new angles: (1) we investigate each scenario's occurrence rates via young star catalogs; (2) we study the features' longevity using over one year of combined data; and (3) we probe the expected color dependency with multi-color photometry. In this process, we also revisit the stellar parameters accounting for activity effects, study stellar flares as activity indicators over year-long time scales, and develop toy models to simulate typical morphologies. We rule out most hypotheses, and only (i) co-rotating material clouds and (ii) spots and misaligned disks remain feasible - with caveats. For (i), co-rotating dust might not be stable enough, while co-rotating gas alone likely cannot cause percentage-scale features; and (ii) would require misaligned disks around most young M dwarfs. We thus suggest a unified hypothesis, a superposition of large-amplitude spot modulations and sharp transits of co-rotating gas clouds. While the complex rotators' mystery remains, these new observations add valuable pieces to the puzzle going forward., Comment: Accepted in The Astronomical Journal, 23 pages, 14 figures, 2 tables. This is the authors' version of the manuscript

Published
2022

35. TOI-1634 b: An Ultra-short-period Keystone Planet Sitting inside the M-dwarf Radius Valley

Author

Gilbert A. Esquerdo, Walter Boschin, Lars A. Buchhave, Allyson Bieryla, Karen A. Collins, Eric L. N. Jensen, Nobuhiko Kusakabe, David F. Phillips, Chelsea X. Huang, Jack J. Lissauer, Steve B. Howell, Norio Narita, E. Girardin, Christopher A. Watson, Enric Palle, Damien Ségransan, R. D. Haywood, P. Guerra, David W. Latham, S. Giacalone, Jonathan Irwin, Avi Shporer, Keivan G. Stassun, Giampaolo Piotto, E. Esparza-Borges, Gloria Andreuzzi, Felipe Murgas, Marco Pedani, Francesco Pepe, Mercedes Lopez-Morales, Scott McDermott, Courtney D. Dressing, Robert Massey, Motohide Tamura, George R. Ricker, Annelies Mortier, Giuseppina Micela, Jessie L. Christiansen, Emilio Molinari, Pau Bosch-Cabot, Jon M. Jenkins, Roland Vanderspek, Aldo F. M. Fiorenzano, Samuel N. Quinn, Hannu Parviainen, Ken Rice, Avet Harutyunyan, Akihiko Fukui, Sara Seager, Elisa V. Quintana, Massimo Cecconi, Mark E. Rose, R. Cloutier, Luca Di Fabrizio, Joshua N. Winn, Alessandro Sozzetti, Arjun B. Savel, Andrew Collier Cameron, David Charbonneau, Rachel A. Matson, Michel Mayor, Dimitar Sasselov, Christophe Lovis, Stéphane Udry, Gábor Fűrész, Xavier Dumusque, Cloutier, R [0000-0001-5383-9393], Charbonneau, D [0000-0002-9003-484X], Stassun, KG [0000-0002-3481-9052], Murgas, F [0000-0001-9087-1245], Mortier, A [0000-0001-7254-4363], Massey, R [0000-0001-8879-7138], Lissauer, JJ [0000-0001-6513-1659], Latham, DW [0000-0001-9911-7388], Haywood, RD [0000-0001-9140-3574], Guerra, P [0000-0002-4308-2339], Giacalone, SA [0000-0002-8965-3969], Bieryla, A [0000-0001-6637-5401], Winn, J [0000-0002-4265-047X], Watson, CA [0000-0002-9718-3266], Vanderspek, R [0000-0001-6763-6562], Udry, S [0000-0001-7576-6236], Tamura, M [0000-0002-6510-0681], Sozzetti, A [0000-0002-7504-365X], Shporer, A [0000-0002-1836-3120], Ségransan, D [0000-0003-2355-8034], Seager, S [0000-0002-6892-6948], Savel, AB [0000-0002-2454-768X], Sasselov, D [0000-0001-7014-1771], Rose, M [0000-0003-4724-745X], Ricker, G [0000-0003-2058-6662], Rice, K [0000-0002-6379-9185], Quintana, EV [0000-0003-1309-2904], Quinn, SN [0000-0002-8964-8377], Piotto, G [0000-0002-9937-6387], Phillips, D [0000-0001-5132-1339], Pedani, M [0000-0002-5752-6260], Parviainen, H [0000-0001-5519-1391], Palle, E [0000-0003-0987-1593], Narita, N [0000-0001-8511-2981], Molinari, E [0000-0002-1742-7735], Micela, G [0000-0002-9900-4751], Mayor, M [0000-0002-9352-5935], Matson, RA [0000-0001-7233-7508], López-Morales, M [0000-0003-3204-8183], Kusakabe, N [0000-0001-9194-1268], Jensen, ELN [0000-0002-4625-7333], Jenkins, JM [0000-0002-4715-9460], Huang, CX [0000-0003-0918-7484], Howell, SB [0000-0002-2532-2853], Fukui, A [0000-0002-4909-5763], Esquerdo, GA [0000-0002-9789-5474], Esparza-Borges, E [0000-0002-2341-3233], Dumusque, X [0000-0002-9332-2011], Dressing, CD [0000-0001-8189-0233], Collins, KA [0000-0001-6588-9574], Cameron, AC [0000-0002-8863-7828], Christiansen, JL [0000-0002-8035-4778], Buchhave, LA [0000-0003-1605-5666], Boschin, W [0000-0001-9978-9109], Apollo - University of Cambridge Repository, 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
Physics, Earth and Planetary Astrophysics (astro-ph.EP), Radial velocity, Astronomy, FOS: Physical sciences, Astronomy and Astrophysics, Radius, 3rd-DAS, Sitting, Exoplantet strcuture, QC Physics, Space and Planetary Science, Planet, astro-ph.EP, Period (geology), QB Astronomy, Planetary system formation, Low mass stars, Astrophysics::Earth and Planetary Astrophysics, Transit photometry, QC, Astrophysics::Galaxy Astrophysics, Astrophysics - Earth and Planetary Astrophysics, QB
Abstract

Studies of close-in planets orbiting M dwarfs have suggested that the M dwarf radius valley may be well-explained by distinct formation timescales between enveloped terrestrials, and rocky planets that form at late times in a gas-depleted environment. This scenario is at odds with the picture that close-in rocky planets form with a primordial gaseous envelope that is subsequently stripped away by some thermally-driven mass loss process. These two physical scenarios make unique predictions of the rocky/enveloped transition's dependence on orbital separation such that studying the compositions of planets within the M dwarf radius valley may be able to establish the dominant physics. Here, we present the discovery of one such keystone planet: the ultra-short period planet TOI-1634 b ($P=0.989$ days, $F=121 F_{\oplus}$, $r_p = 1.790^{+0.080}_{-0.081} R_{\oplus}$) orbiting a nearby M2 dwarf ($K_s=8.7$, $R_s=0.45 R_{\odot}$, $M_s=0.50 M_{\odot}$) and whose size and orbital period sit within the M dwarf radius valley. We confirm the TESS-discovered planet candidate using extensive ground-based follow-up campaigns, including a set of 32 precise radial velocity measurements from HARPS-N. We measure a planetary mass of $4.91^{+0.68}_{-0.70} M_{\oplus}$, which makes TOI-1634 b inconsistent with an Earth-like composition at $5.9\sigma$ and thus requires either an extended gaseous envelope, a large volatile-rich layer, or a rocky portion that is not dominated by iron and silicates to explain its mass and radius. The discovery that the bulk composition of TOI-1634 b is inconsistent with that of the Earth favors the gas-depleted formation mechanism to explain the emergence of the radius valley around M dwarfs with $M_s\lesssim 0.5 M_{\odot}$., Comment: 27 pages, 13 figures, accepted to AAS journals. Our time series are included as a csv file in the arXiv source files

Published
2021

36. Detection Limits of Low-mass, Long-period Exoplanets Using Gaussian Processes Applied to HARPS-N Solar Radial Velocities

Author

Christopher A. Watson, M. Lopez-Morales, Massimo Cecconi, L. Malavolta, R. D. Haywood, Timothy Milbourne, M. Gonzalez, Dimitar Sasselov, David F. Phillips, Xavier Dumusque, J. Maldonado, Ken Rice, H. M. Cegla, S. H. Saar, Stéphane Udry, Rosario Cosentino, D. W. Latham, N. Buchschacher, Elisa Molinari, Ronald L. Walsworth, Adriano Ghedina, Giuseppina Micela, Francesco Pepe, Alessandro Sozzetti, C. H. Li, Susan E. Thompson, D. Charbonneau, E. Poretti, Annelies Mortier, Nicholas Langellier, A. Collier Cameron, Marcello Lodi, Langellier, N [0000-0003-2107-3308], Milbourne, TW [0000-0001-5446-7712], Phillips, DF [0000-0001-5132-1339], Haywood, RD [0000-0001-9140-3574], Saar, SH [0000-0001-7032-8480], Mortier, A [0000-0001-7254-4363], Malavolta, L [0000-0002-6492-2085], Thompson, S [0000-0002-8039-194X], Cameron, AC [0000-0002-8863-7828], Dumusque, X [0000-0002-9332-2011], Cegla, HM [0000-0001-8934-7315], Latham, DW [0000-0001-9911-7388], Maldonado, J [0000-0002-2218-5689], Buchschacher, N [0000-0002-3697-1541], Cecconi, M [0000-0001-5701-2529], Charbonneau, D [0000-0002-9003-484X], Cosentino, R [0000-0003-1784-1431], Ghedina, A [0000-0003-4702-5152], Lodi, M [0000-0002-5432-9659], López-Morales, M [0000-0003-3204-8183], Micela, G [0000-0002-9900-4751], Molinari, E [0000-0002-1742-7735], Poretti, E [0000-0003-1200-0473], Rice, K [0000-0002-6379-9185], Sasselov, D [0000-0001-7014-1771], Sozzetti, A [0000-0002-7504-365X], Udry, S [0000-0001-7576-6236], Walsworth, RL [0000-0003-0311-4751], Apollo - University of Cambridge Repository, 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
Radial velocity, astro-ph.SR, Solar activity, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, 010309 optics, symbols.namesake, Long period, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, Gaussian regression, 010303 astronomy & astrophysics, Gaussian process, QC, Astrophysics::Galaxy Astrophysics, QB, Physics, Detection limit, Exoplanets, DAS, Astronomy and Astrophysics, Exoplanet, QC Physics, 13. Climate action, Space and Planetary Science, astro-ph.EP, symbols, Astrophysics::Earth and Planetary Astrophysics, Low Mass, astro-ph.IM
Abstract

Funding: A.C.C. acknowledges support from the Science and Technology Facilities Council (STFC) consolidated grant No. ST/R000824/1. Radial velocity (RV) searches for Earth-mass exoplanets in the habitable zone around Sun-like stars are limited by the effects of stellar variability on the host star. In particular, suppression of convective blueshift and brightness inhomogeneities due to photospheric faculae/plage and starspots are the dominant contribution to the variability of such stellar RVs. Gaussian process (GP) regression is a powerful tool for statistically modeling these quasi-periodic variations. We investigate the limits of this technique using 800 days of RVs from the solar telescope on the High Accuracy Radial velocity Planet Searcher for the Northern hemisphere (HARPS-N) spectrograph. These data provide a well-sampled time series of stellar RV variations. Into this data set, we inject Keplerian signals with periods between 100 and 500 days and amplitudes between 0.6 and 2.4 m s−1. We use GP regression to fit the resulting RVs and determine the statistical significance of recovered periods and amplitudes. We then generate synthetic RVs with the same covariance properties as the solar data to determine a lower bound on the observational baseline necessary to detect low-mass planets in Venus-like orbits around a Sun-like star. Our simulations show that discovering planets with a larger mass (~0.5 m s−1) using current-generation spectrographs and GP regression will require more than 12 yr of densely sampled RV observations. Furthermore, even with a perfect model of stellar variability, discovering a true exo-Venus (~0.1 m s−1) with current instruments would take over 15 yr. Therefore, next-generation spectrographs and better models of stellar variability are required for detection of such planets. Postprint

Published
2021

37. Wolf 503 b: Characterization of a Sub-Neptune Orbiting a Metal-Poor K Dwarf

Author

Lauren M. Weiss, Ian J. M. Crossfield, Sean M. Mills, Mercedes Lopez-Morales, Björn Benneke, Johanna Teske, Varoujan Gorjian, Howard Isaacson, Sharon X. Wang, Emilio Molinari, Samuel K. Grunblatt, R. Paul Butler, Jennifer Burt, Ashley Chontos, Grzegorz Nowak, Aida Behmard, Stephen A. Shectman, Erik A. Petigura, Avet Harutyunyan, Annelies Mortier, Ennio Poretti, Xavier Dumusque, Michel Mayor, Andrew W. Howard, Molly R. Kosiarek, Evangelos Nagel, Rafael Luque, Jeffrey D. Crane, Enric Palle, David W. Latham, Adriano Ghedina, Aldo S. Bonomo, Benjamin J. Fulton, Rosario Cosentino, Sarah Blunt, Aldo F. M. Fiorenzano, Alessandro Sozzetti, Alex S. Polanski, Polanski, AS [0000-0001-7047-8681], Burt, JA [0000-0002-0040-6815], Nowak, G [0000-0002-7031-7754], López-Morales, M [0000-0003-3204-8183], Mortier, A [0000-0001-7254-4363], Poretti, E [0000-0003-1200-0473], Behmard, A [0000-0003-0012-9093], Benneke, B [0000-0001-5578-1498], Blunt, S [0000-0002-3199-2888], Bonomo, AS [0000-0002-6177-198X], Butler, RP [0000-0003-1305-3761], Chontos, A [0000-0003-1125-2564], Crane, JD [0000-0002-5226-787X], Dumusque, X [0000-0002-9332-2011], Fulton, BJ [0000-0003-3504-5316], Ghedina, A [0000-0003-4702-5152], Grunblatt, SK [0000-0003-4976-9980], Howard, AW [0000-0001-8638-0320], Isaacson, H [0000-0002-0531-1073], Kosiarek, MR [0000-0002-6115-4359], Latham, DW [0000-0001-9911-7388], Luque, R [0000-0002-4671-2957], Mayor, M [0000-0002-9352-5935], Mills, SM [0000-0002-4535-6241], Molinari, E [0000-0002-1742-7735], Nagel, E [0000-0002-4019-3631], Pallé, E [0000-0003-0987-1593], Petigura, EA [0000-0003-0967-2893], Shectman, SA [0000-0002-8681-6136], Sozzetti, A [0000-0002-7504-365X], Wang, SX [0000-0002-6937-9034], Weiss, LM [0000-0002-3725-3058], and Apollo - University of Cambridge Repository

Subjects
Physics, Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astronomy and Astrophysics, Radius, Astrophysics, Characterization (mathematics), 01 natural sciences, 010309 optics, Transmission spectroscopy, Radial velocity, Photometry (optics), Space and Planetary Science, Neptune, 0103 physical sciences, astro-ph.EP, Eccentricity (mathematics), 010303 astronomy & astrophysics, Mass fraction, Astrophysics - Earth and Planetary Astrophysics
Abstract

Using radial velocity measurements from four instruments, we report the mass and density of a $2.043\pm0.069 ~\rm{R}_{\oplus}$ sub-Neptune orbiting the quiet K-dwarf Wolf 503 (HIP 67285). In addition, we present improved orbital and transit parameters by analyzing previously unused short-cadence $K2$ campaign 17 photometry and conduct a joint radial velocity-transit fit to constrain the eccentricity at $0.41\pm0.05$. The addition of a transit observation by $Spitzer$ also allows us to refine the orbital ephemeris in anticipation of further follow-up. Our mass determination, $6.26^{+0.69}_{-0.70}~\rm{M}_{\odot}$, in combination with the updated radius measurements, gives Wolf 503 b a bulk density of $\rho = 2.92\pm ^{+0.50}_{-0.44}$ $\rm{g}~\rm{cm}^{-3}$. Using interior composition models, we find this density is consistent with an Earth-like core with either a substantial $\rm{H}_2\rm{O}$ mass fraction ($45^{+19.12}_{-16.15}\%$) or a modest H/He envelope ($0.5\pm0.28\%$). The low H/He mass fraction, along with the old age of Wolf 503 ($11\pm2$ Gyrs), makes this sub-Neptune an opportune subject for testing theories of XUV-driven mass loss while the brightness of its host ($J=8.3$ mag) makes it an attractive target for transmission spectroscopy., Comment: Accepted to ApJ 2021 July 15

Published
2021
Full Text
View/download PDF

38. 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

39. Identifying Exoplanets with Deep Learning. IV. Removing Stellar Activity Signals from Radial Velocity Measurements Using Neural Networks

Author

Zoe. L. de Beurs, Andrew Vanderburg, Christopher J. Shallue, Xavier Dumusque, Andrew Collier Cameron, Christopher Leet, Lars A. Buchhave, Rosario Cosentino, Adriano Ghedina, Raphaëlle D. Haywood, Nicholas Langellier, David W. Latham, Mercedes López-Morales, Michel Mayor, Giusi Micela, Timothy W. Milbourne, Annelies Mortier, Emilio Molinari, Francesco Pepe, David F. Phillips, Matteo Pinamonti, Giampaolo Piotto, Ken Rice, Dimitar Sasselov, Alessandro Sozzetti, Stéphane Udry, Christopher A. Watson, De Beurs, ZL [0000-0002-7564-6047], Vanderburg, A [0000-0001-7246-5438], Shallue, CJ [0000-0002-7585-9974], Dumusque, X [0000-0002-9332-2011], Cameron, AC [0000-0002-8863-7828], Leet, C [0000-0003-2369-0481], Buchhave, LA [0000-0003-1605-5666], Cosentino, R [0000-0003-1784-1431], Ghedina, A [0000-0003-4702-5152], Haywood, RD [0000-0001-9140-3574], Langellier, N [0000-0003-2107-3308], Latham, DW [0000-0001-9911-7388], López-Morales, M [0000-0003-3204-8183], Mayor, M [0000-0002-9352-5935], Micela, G [0000-0002-9900-4751], Milbourne, TW [0000-0001-5446-7712], Mortier, A [0000-0001-7254-4363], Molinari, E [0000-0002-1742-7735], Phillips, DF [0000-0001-5132-1339], Pinamonti, M [0000-0002-4445-1845], Piotto, G [0000-0002-9937-6387], Rice, K [0000-0002-6379-9185], Sasselov, D [0000-0001-7014-1771], Sozzetti, A [0000-0002-7504-365X], Udry, S [0000-0001-7576-6236], Apollo - University of Cambridge Repository, Apollo-University Of Cambridge Repository, 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
QA75, FOS: Computer and information sciences, Radial velocity, Computer Science - Machine Learning, astro-ph.SR, Exoplanet astronomy, QA75 Electronic computers. Computer science, cs.LG, FOS: Physical sciences, Machine Learning (cs.LG), QB Astronomy, Instrumentation and Methods for Astrophysics (astro-ph.IM), QC, Solar and Stellar Astrophysics (astro-ph.SR), QB, Earth and Planetary Astrophysics (astro-ph.EP), The Solar System, Exoplanets, and Astrobiology, Astronomy and Astrophysics, DAS, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, astro-ph.EP, Convolutional neural networks, Astrophysics - Instrumentation and Methods for Astrophysics, astro-ph.IM, Astrophysics - Earth and Planetary Astrophysics
Abstract

Exoplanet detection with precise radial velocity (RV) observations is currently limited by spurious RV signals introduced by stellar activity. We show that machine learning techniques such as linear regression and neural networks can effectively remove the activity signals (due to starspots/faculae) from RV observations. Previous efforts focused on carefully filtering out activity signals in time using modeling techniques like Gaussian Process regression (e.g. Haywood et al. 2014). Instead, we systematically remove activity signals using only changes to the average shape of spectral lines, and no information about when the observations were collected. We trained our machine learning models on both simulated data (generated with the SOAP 2.0 software; Dumusque et al. 2014) and observations of the Sun from the HARPS-N Solar Telescope (Dumusque et al. 2015; Phillips et al. 2016; Collier Cameron et al. 2019). We find that these techniques can predict and remove stellar activity from both simulated data (improving RV scatter from 82 cm/s to 3 cm/s) and from more than 600 real observations taken nearly daily over three years with the HARPS-N Solar Telescope (improving the RV scatter from 1.753 m/s to 1.039 m/s, a factor of ~ 1.7 improvement). In the future, these or similar techniques could remove activity signals from observations of stars outside our solar system and eventually help detect habitable-zone Earth-mass exoplanets around Sun-like stars., Comment: 28 pages, 14 figures, Accepted for publication in the Astronomical Journal

Published
2020
Full Text
View/download PDF

40. TESS Hunt for Young and Maturing Exoplanets (THYME) III: a two-planet system in the 400 Myr Ursa Major Group

Author

Pa Chia Thao, Silvano Desidera, Elisabeth R. Newton, Ivan Terentev, Roland Vanderspek, Martti H. Kristiansen, Peter Tenenbaum, Aaron C. Rizzuto, Eric E. Mamajek, Andrew W. Mann, David W. Latham, George R. Ricker, Nezar Hazam Sallam, John P. Doty, Douglas A. Caldwell, Francesco Pepe, Joseph D. Twicken, George Zhou, Stephen R. Kane, Michael M. Aitken, Gabriel Murawski, Adam L. Kraus, Gilbert A. Esquerdo, Guillermo Torres, Markus Rabus, Sara Seager, Marshall C. Johnson, Annelies Mortier, Serena Benatti, Bob Massey, Robert Gagliano, Tom Jacobs, Ennio Poretti, Karen A. Collins, Jon M. Jenkins, Ana Glidden, Andrew Vanderburg, Steven Villanueva, Keighley Rockcliffe, Mackenna L. Wood, Thomas Barclay, Thomas G. Wilson, Jonathan L. Bush, Perry Berlind, Rosario Cosentino, Michelle L. Hill, Diana Dragomir, Christophe Lovis, Avet Harutyunyan, Mark Omohundro, Joshua N. Winn, Hans Martin Schwengeler, Samuel N. Quinn, Daryll LaCourse, University of St Andrews. School of Physics and Astronomy, Mann, AW [0000-0003-3654-1602], Johnson, MC [0000-0002-5099-8185], Vanderburg, A [0000-0001-7246-5438], Kraus, AL [0000-0001-9811-568X], Rizzuto, AC [0000-0001-9982-1332], Wood, ML [0000-0001-7336-7725], Bush, JL [0000-0002-9446-9250], Rockcliffe, K [0000-0003-1337-723X], Newton, ER [0000-0003-4150-841X], Latham, DW [0000-0001-9911-7388], Mamajek, EE [0000-0003-2008-1488], Zhou, G [0000-0002-4891-3517], Quinn, SN [0000-0002-8964-8377], Thao, PC [0000-0001-5729-6576], Benatti, S [0000-0002-4638-3495], Desidera, S [0000-0001-8613-2589], Mortier, A [0000-0001-7254-4363], Poretti, E [0000-0003-1200-0473], Wilson, TG [0000-0001-8749-1962], Kristiansen, MH [0000-0002-2607-138X], Gagliano, R [0000-0002-5665-1879], Jacobs, T [0000-0003-3988-3245], Lacourse, DM [0000-0002-8527-2114], Kane, SR [0000-0002-7084-0529], Hill, ML [0000-0002-0139-4756], Rabus, M [0000-0003-2935-7196], Esquerdo, GA [0000-0002-9789-5474], Collins, KA [0000-0001-6588-9574], Murawski, G [0000-0001-7809-1457], Sallam, NH [0000-0003-0614-2571], Aitken, MM [0000-0002-0169-0766], Massey, B [0000-0001-8879-7138], Ricker, GR [0000-0003-2058-6662], Vanderspek, R [0000-0001-6763-6562], Seager, S [0000-0002-6892-6948], Winn, JN [0000-0002-4265-047X], Jenkins, JM [0000-0002-4715-9460], Barclay, T [0000-0001-7139-2724], Caldwell, DA [0000-0003-1963-9616], Dragomir, D [0000-0003-2313-467X], Glidden, A [0000-0002-5322-2315], Tenenbaum, P [0000-0002-1949-4720], Torres, G [0000-0002-5286-0251], Twicken, JD [0000-0002-6778-7552], Villanueva, S [0000-0001-6213-8804], and Apollo - University of Cambridge Repository

Subjects
ComputerSystemsOrganization_COMPUTERSYSTEMIMPLEMENTATION, 010504 meteorology & atmospheric sciences, Exoplanet astronomy, Exoplanet evolution, Library science, FOS: Physical sciences, ComputerApplications_COMPUTERSINOTHERSYSTEMS, Astrophysics::Cosmology and Extragalactic Astrophysics, 5109 Space Sciences, 01 natural sciences, Transits, 0103 physical sciences, QB Astronomy, Astrophysics::Solar and Stellar Astrophysics, Stellar rotation, 010303 astronomy & astrophysics, QC, Astrophysics::Galaxy Astrophysics, Computer Science::Databases, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, Stellar activity, QB, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Exoplanet dynamics, Astronomy and Astrophysics, 3rd-DAS, Exoplanet, Young star clusters, Graduate research, QC Physics, Astrophysics - Solar and Stellar Astrophysics, Space and Planetary Science, 5101 Astronomical Sciences, Astrophysics::Earth and Planetary Astrophysics, 51 Physical Sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

Exoplanets can evolve significantly between birth and maturity, as their atmospheres, orbits, and structures are shaped by their environment. Young planets ($, Comment: Published in AJ. Oct 19: fixed a citation issue

Published
2020
Full Text
View/download PDF

41. An 11 Earth-mass, Long-period Sub-Neptune Orbiting a Sun-like Star

Author

Alessandro Sozzetti, Charles D. Fortenbach, Mario Damasso, David W. Latham, Rosario Cosentino, Emilio Molinari, David Charbonneau, Lars A. Buchhave, Ken Rice, Annelies Mortier, A. F. Martinez Fiorenzano, David F. Phillips, Suzanne Aigrain, Giuseppina Micela, Raphaëlle D. Haywood, Stéphane Udry, Ennio Poretti, Aldo S. Bonomo, Vinesh Rajpaul, Logan A. Pearce, Courtney D. Dressing, Giampaolo Piotto, Luca Malavolta, Li Zeng, Mercedes Lopez-Morales, Francesco Pepe, A. Coffinet, Andrew Collier Cameron, Xavier Dumusque, Andrew W. Mayo, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, University of St Andrews. St Andrews Centre for Exoplanet Science, Mayo, AW [0000-0002-7216-2135], Buchhave, LA [0000-0003-1605-5666], Dressing, CD [0000-0001-8189-0233], Mortier, A [0000-0001-7254-4363], Zeng, L [0000-0003-1957-6635], Fortenbach, CD [0000-0001-5286-639X], Aigrain, S [0000-0003-1453-0574], Bonomo, AS [0000-0002-6177-198X], Cameron, AC [0000-0002-8863-7828], Charbonneau, D [0000-0002-9003-484X], Dumusque, X [0000-0002-9332-2011], Haywood, RD [0000-0001-9140-3574], Latham, DW [0000-0001-9911-7388], López-Morales, M [0000-0003-3204-8183], Malavolta, L [0000-0002-6492-2085], Molinari, E [0000-0002-1742-7735], Pearce, L [0000-0003-3904-7378], Piotto, G [0000-0002-9937-6387], Poretti, E [0000-0003-1200-0473], Sozzetti, A [0000-0002-7504-365X], and Apollo - University of Cambridge Repository

Subjects
planets and satellites: detection, Planetary equilibrium temperature, 010504 meteorology & atmospheric sciences, fundamental parameters [Planets and satellites], FOS: Physical sciences, Astrophysics, 01 natural sciences, techniques: photometric, Planet, Neptune, techniques: radial velocities, 0103 physical sciences, QB Astronomy, planets and satellites: composition, planets and satellites: fundamental parameters, planets and satellites: gaseous planets, methods: data analysis, data analysis [Methods], 010303 astronomy & astrophysics, QB, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Physics, radial velocities [Techniques], photometric [Techniques], Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, 3rd-DAS, Earth mass, Exoplanet, Radial velocity, detection [Planets and satellites], gaseous planets [Planets and satellites], Photometry (astronomy), 13. Climate action, Space and Planetary Science, astro-ph.EP, composition [Planets and satellites], Astrophysics::Earth and Planetary Astrophysics, Planetary mass, Astrophysics - Earth and Planetary Astrophysics
Abstract

Although several thousands of exoplanets have now been detected and characterized, observational biases have led to a paucity of long-period, low-mass exoplanets with measured masses and a corresponding lag in our understanding of such planets. In this paper we report the mass estimation and characterization of the long-period exoplanet Kepler-538b. This planet orbits a Sun-like star (V = 11.27) with M_* = 0.892 +/- (0.051, 0.035) M_sun and R_* = 0.8717 +/- (0.0064, 0.0061) R_sun. Kepler-538b is a 2.215 +/- (0.040, 0.034) R_earth sub-Neptune with a period of P = 81.73778 +/- 0.00013 d. It is the only known planet in the system. We collected radial velocity (RV) observations with HIRES on Keck I and HARPS-N on the TNG. We characterized stellar activity by a Gaussian process with a quasi-periodic kernel applied to our RV and cross correlation function full width at half maximum (FWHM) observations. By simultaneously modeling Kepler photometry, RV, and FWHM observations, we found a semi-amplitude of K = 1.68 +/- (0.39, 0.38) m s^-1 and a planet mass of M_p = 10.6 +/- (2.5, 2.4) M_earth. Kepler-538b is the smallest planet beyond P = 50 d with an RV mass measurement. The planet likely consists of a significant fraction of ices (dominated by water ice), in addition to rocks/metals, and a small amount of gas. Sophisticated modeling techniques such as those used in this paper, combined with future spectrographs with ultra high-precision and stability will be vital for yielding more mass measurements in this poorly understood exoplanet regime. This in turn will improve our understanding of the relationship between planet composition and insolation flux and how the rocky to gaseous transition depends on planetary equilibrium temperature., Comment: Published in AJ, 17 pages, 8 figures, 3 tables

Published
2019

42. A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067.

Author

Luque R, Osborn HP, Leleu A, Pallé E, Bonfanti A, Barragán O, Wilson TG, Broeg C, Cameron AC, Lendl M, Maxted PFL, Alibert Y, Gandolfi D, Delisle JB, Hooton MJ, Egger JA, Nowak G, Lafarga M, Rapetti D, Twicken JD, Morales JC, Carleo I, Orell-Miquel J, Adibekyan V, Alonso R, Alqasim A, Amado PJ, Anderson DR, Anglada-Escudé G, Bandy T, Bárczy T, Barrado Navascues D, Barros SCC, Baumjohann W, Bayliss D, Bean JL, Beck M, Beck T, Benz W, Billot N, Bonfils X, Borsato L, Boyle AW, Brandeker A, Bryant EM, Cabrera J, Carrazco-Gaxiola S, Charbonneau D, Charnoz S, Ciardi DR, Cochran WD, Collins KA, Crossfield IJM, Csizmadia S, Cubillos PE, Dai F, Davies MB, Deeg HJ, Deleuil M, Deline A, Delrez L, Demangeon ODS, Demory BO, Ehrenreich D, Erikson A, Esparza-Borges E, Falk B, Fortier A, Fossati L, Fridlund M, Fukui A, Garcia-Mejia J, Gill S, Gillon M, Goffo E, Gómez Maqueo Chew Y, Güdel M, Guenther EW, Günther MN, Hatzes AP, Helling C, Hesse KM, Howell SB, Hoyer S, Ikuta K, Isaak KG, Jenkins JM, Kagetani T, Kiss LL, Kodama T, Korth J, Lam KWF, Laskar J, Latham DW, Lecavelier des Etangs A, Leon JPD, Livingston JH, Magrin D, Matson RA, Matthews EC, Mordasini C, Mori M, Moyano M, Munari M, Murgas F, Narita N, Nascimbeni V, Olofsson G, Osborne HLM, Ottensamer R, Pagano I, Parviainen H, Peter G, Piotto G, Pollacco D, Queloz D, Quinn SN, Quirrenbach A, Ragazzoni R, Rando N, Ratti F, Rauer H, Redfield S, Ribas I, Ricker GR, Rudat A, Sabin L, Salmon S, Santos NC, Scandariato G, Schanche N, Schlieder JE, Seager S, Ségransan D, Shporer A, Simon AE, Smith AMS, Sousa SG, Stalport M, Szabó GM, Thomas N, Tuson A, Udry S, Vanderburg AM, Van Eylen V, Van Grootel V, Venturini J, Walter I, Walton NA, Watanabe N, Winn JN, and Zingales T

Abstract

Planets with radii between that of the Earth and Neptune (hereafter referred to as 'sub-Neptunes') are found in close-in orbits around more than half of all Sun-like stars 1,2 . However, their composition, formation and evolution remain poorly understood 3 . The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD 110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R ⊕ to 2.85R ⊕ . Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2023
Full Text
View/download PDF

43. A temperate Earth-sized planet with tidal heating transiting an M6 star.

Author

Peterson MS, Benneke B, Collins K, Piaulet C, Crossfield IJM, Ali-Dib M, Christiansen JL, Gagné J, Faherty J, Kite E, Dressing C, Charbonneau D, Murgas F, Cointepas M, Almenara JM, Bonfils X, Kane S, Werner MW, Gorjian V, Roy PA, Shporer A, Pozuelos FJ, Socia QJ, Cloutier R, Dietrich J, Irwin J, Weiss L, Waalkes W, Berta-Thomson Z, Evans T, Apai D, Parviainen H, Pallé E, Narita N, Howard AW, Dragomir D, Barkaoui K, Gillon M, Jehin E, Ducrot E, Benkhaldoun Z, Fukui A, Mori M, Nishiumi T, Kawauchi K, Ricker G, Latham DW, Winn JN, Seager S, Isaacson H, Bixel A, Gibbs A, Jenkins JM, Smith JC, Chavez JP, Rackham BV, Henning T, Gabor P, Chen WP, Espinoza N, Jensen ELN, Collins KI, Schwarz RP, Conti DM, Wang G, Kielkopf JF, Mao S, Horne K, Sefako R, Quinn SN, Moldovan D, Fausnaugh M, Fűűrész G, and Barclay T

Abstract

Temperate Earth-sized exoplanets around late-M dwarfs offer a rare opportunity to explore under which conditions planets can develop hospitable climate conditions. The small stellar radius amplifies the atmospheric transit signature, making even compact secondary atmospheres dominated by N 2 or CO 2 amenable to characterization with existing instrumentation 1 . Yet, despite large planet search efforts 2 , detection of low-temperature Earth-sized planets around late-M dwarfs has remained rare and the TRAPPIST-1 system, a resonance chain of rocky planets with seemingly identical compositions, has not yet shown any evidence of volatiles in the system 3 . Here we report the discovery of a temperate Earth-sized planet orbiting the cool M6 dwarf LP 791-18. The newly discovered planet, LP 791-18d, has a radius of 1.03 ± 0.04 R ⊕ and an equilibrium temperature of 300-400 K, with the permanent night side plausibly allowing for water condensation. LP 791-18d is part of a coplanar system 4 and provides a so-far unique opportunity to investigate a temperate exo-Earth in a system with a sub-Neptune that retained its gas or volatile envelope. On the basis of observations of transit timing variations, we find a mass of 7.1 ± 0.7 M ⊕ for the sub-Neptune LP 791-18c and a mass of [Formula: see text] for the exo-Earth LP 791-18d. The gravitational interaction with the sub-Neptune prevents the complete circularization of LP 791-18d's orbit, resulting in continued tidal heating of LP 791-18d's interior and probably strong volcanic activity at the surface 5,6 ., (© 2023. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2023
Full Text
View/download PDF

44. GJ 367b: A dense, ultrashort-period sub-Earth planet transiting a nearby red dwarf star.

Author

Lam KWF, Csizmadia S, Astudillo-Defru N, Bonfils X, Gandolfi D, Padovan S, Esposito M, Hellier C, Hirano T, Livingston J, Murgas F, Smith AMS, Collins KA, Mathur S, Garcia RA, Howell SB, Santos NC, Dai F, Ricker GR, Vanderspek R, Latham DW, Seager S, Winn JN, Jenkins JM, Albrecht S, Almenara JM, Artigau E, Barragán O, Bouchy F, Cabrera J, Charbonneau D, Chaturvedi P, Chaushev A, Christiansen JL, Cochran WD, De Meideiros JR, Delfosse X, Díaz RF, Doyon R, Eigmüller P, Figueira P, Forveille T, Fridlund M, Gaisné G, Goffo E, Georgieva I, Grziwa S, Guenther E, Hatzes AP, Johnson MC, Kabáth P, Knudstrup E, Korth J, Lewin P, Lissauer JJ, Lovis C, Luque R, Melo C, Morgan EH, Morris R, Mayor M, Narita N, Osborne HLM, Palle E, Pepe F, Persson CM, Quinn SN, Rauer H, Redfield S, Schlieder JE, Ségransan D, Serrano LM, Smith JC, Šubjak J, Twicken JD, Udry S, Van Eylen V, and Vezie M

Abstract

Ultrashort-period (USP) exoplanets have orbital periods shorter than 1 day. Precise masses and radii of USP exoplanets 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 of 10.2), nearby, and red (M-type) dwarf star every 7.7 hours. GJ 367b has a radius of 0.718 ± 0.054 Earth-radii and a mass of 0.546 ± 0.078 Earth-masses, making it a sub-Earth planet. The corresponding bulk density is 8.106 ± 2.165 grams per cubic centimeter—close to that of iron. An interior structure model predicts that the planet has an iron core radius fraction of 86 ± 5%, similar to that of Mercury’s interior.

Published
2021
Full Text
View/download PDF

45. A nearby transiting rocky exoplanet that is suitable for atmospheric investigation.

Author

Trifonov T, Caballero JA, Morales JC, Seifahrt A, Ribas I, Reiners A, Bean JL, Luque R, Parviainen H, Pallé E, Stock S, Zechmeister M, Amado PJ, Anglada-Escudé G, Azzaro M, Barclay T, Béjar VJS, Bluhm P, Casasayas-Barris N, Cifuentes C, Collins KA, Collins KI, Cortés-Contreras M, de Leon J, Dreizler S, Dressing CD, Esparza-Borges E, Espinoza N, Fausnaugh M, Fukui A, Hatzes AP, Hellier C, Henning T, Henze CE, Herrero E, Jeffers SV, Jenkins JM, Jensen ELN, Kaminski A, Kasper D, Kossakowski D, Kürster M, Lafarga M, Latham DW, Mann AW, Molaverdikhani K, Montes D, Montet BT, Murgas F, Narita N, Oshagh M, Passegger VM, Pollacco D, Quinn SN, Quirrenbach A, Ricker GR, Rodríguez López C, Sanz-Forcada J, Schwarz RP, Schweitzer A, Seager S, Shporer A, Stangret M, Stürmer J, Tan TG, Tenenbaum P, Twicken JD, Vanderspek R, and Winn JN

Abstract

Spectroscopy of transiting exoplanets can be used to investigate their atmospheric properties and habitability. Combining radial velocity (RV) and transit data provides additional information on exoplanet physical properties. We detect a transiting rocky planet with an orbital period of 1.467 days around the nearby red dwarf star Gliese 486. The planet Gliese 486 b is 2.81 Earth masses and 1.31 Earth radii, with uncertainties of 5%, as determined from RV data and photometric light curves. The host star is at a distance of ~8.1 parsecs, has a J -band magnitude of ~7.2, and is observable from both hemispheres of Earth. On the basis of these properties and the planet's short orbital period and high equilibrium temperature, we show that this terrestrial planet is suitable for emission and transit spectroscopy., (Copyright © 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Published
2021
Full Text
View/download PDF

46. A giant planet candidate transiting a white dwarf.

Author

Vanderburg A, Rappaport SA, Xu S, Crossfield IJM, Becker JC, Gary B, Murgas F, Blouin S, Kaye TG, Palle E, Melis C, Morris BM, Kreidberg L, Gorjian V, Morley CV, Mann AW, Parviainen H, Pearce LA, Newton ER, Carrillo A, Zuckerman B, Nelson L, Zeimann G, Brown WR, Tronsgaard R, Klein B, Ricker GR, Vanderspek RK, Latham DW, Seager S, Winn JN, Jenkins JM, Adams FC, Benneke B, Berardo D, Buchhave LA, Caldwell DA, Christiansen JL, Collins KA, Colón KD, Daylan T, Doty J, Doyle AE, Dragomir D, Dressing C, Dufour P, Fukui A, Glidden A, Guerrero NM, Guo X, Heng K, Henriksen AI, Huang CX, Kaltenegger L, Kane SR, Lewis JA, Lissauer JJ, Morales F, Narita N, Pepper J, Rose ME, Smith JC, Stassun KG, and Yu L

Abstract

Astronomers have discovered thousands of planets outside the Solar System 1 , most of which orbit stars that will eventually evolve into red giants and then into white dwarfs. During the red giant phase, any close-orbiting planets will be engulfed by the star 2 , but more distant planets can survive this phase and remain in orbit around the white dwarf 3,4 . Some white dwarfs show evidence for rocky material floating in their atmospheres 5 , in warm debris disks 6-9 or orbiting very closely 10-12 , which has been interpreted as the debris of rocky planets that were scattered inwards and tidally disrupted 13 . Recently, the discovery of a gaseous debris disk with a composition similar to that of ice giant planets 14 demonstrated that massive planets might also find their way into tight orbits around white dwarfs, but it is unclear whether these planets can survive the journey. So far, no intact planets have been detected in close orbits around white dwarfs. Here we report the observation of a giant planet candidate transiting the white dwarf WD 1856+534 (TIC 267574918) every 1.4 days. We observed and modelled the periodic dimming of the white dwarf caused by the planet candidate passing in front of the star in its orbit. The planet candidate is roughly the same size as Jupiter and is no more than 14 times as massive (with 95 per cent confidence). Other cases of white dwarfs with close brown dwarf or stellar companions are explained as the consequence of common-envelope evolution, wherein the original orbit is enveloped during the red giant phase and shrinks owing to friction. In this case, however, the long orbital period (compared with other white dwarfs with close brown dwarf or stellar companions) and low mass of the planet candidate make common-envelope evolution less likely. Instead, our findings for the WD 1856+534 system indicate that giant planets can be scattered into tight orbits without being tidally disrupted, motivating the search for smaller transiting planets around white dwarfs.

Published
2020
Full Text
View/download PDF

47. Publisher Correction: A planet within the debris disk around the pre-main-sequence star AU Microscopii.

Author

Plavchan P, Barclay T, Gagné J, Gao P, Cale B, Matzko W, Dragomir D, Quinn S, Feliz D, Stassun K, Crossfield IJM, Berardo DA, Latham DW, Tieu B, Anglada-Escudé G, Ricker G, Vanderspek R, Seager S, Winn JN, Jenkins JM, Rinehart S, Krishnamurthy A, Dynes S, Doty J, Adams F, Afanasev DA, Beichman C, Bottom M, Bowler BP, Brinkworth C, Brown CJ, Cancino A, Ciardi DR, Clampin M, Clark JT, Collins K, Davison C, Foreman-Mackey D, Furlan E, Gaidos EJ, Geneser C, Giddens F, Gilbert E, Hall R, Hellier C, Henry T, Horner J, Howard AW, Huang C, Huber J, Kane SR, Kenworthy M, Kielkopf J, Kipping D, Klenke C, Kruse E, Latouf N, Lowrance P, Mennesson B, Mengel M, Mills SM, Morton T, Narita N, Newton E, Nishimoto A, Okumura J, Palle E, Pepper J, Quintana EV, Roberge A, Roccatagliata V, Schlieder JE, Tanner A, Teske J, Tinney CG, Vanderburg A, von Braun K, Walp B, Wang J, Wang SX, Weigand D, White R, Wittenmyer RA, Wright DJ, Youngblood A, Zhang H, and Zilberman P

Abstract

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Published
2020
Full Text
View/download PDF

48. A remnant planetary core in the hot-Neptune desert.

Author

Armstrong DJ, Lopez TA, Adibekyan V, Booth RA, Bryant EM, Collins KA, Deleuil M, Emsenhuber A, Huang CX, King GW, Lillo-Box J, Lissauer JJ, Matthews E, Mousis O, Nielsen LD, Osborn H, Otegi J, Santos NC, Sousa SG, Stassun KG, Veras D, Ziegler C, Acton JS, Almenara JM, Anderson DR, Barrado D, Barros SCC, Bayliss D, Belardi C, Bouchy F, Briceño C, Brogi M, Brown DJA, Burleigh MR, Casewell SL, Chaushev A, Ciardi DR, Collins KI, Colón KD, Cooke BF, Crossfield IJM, Díaz RF, Mena ED, Demangeon ODS, Dorn C, Dumusque X, Eigmüller P, Fausnaugh M, Figueira P, Gan T, Gandhi S, Gill S, Gonzales EJ, Goad MR, Günther MN, Helled R, Hojjatpanah S, Howell SB, Jackman J, Jenkins JS, Jenkins JM, Jensen ELN, Kennedy GM, Latham DW, Law N, Lendl M, Lozovsky M, Mann AW, Moyano M, McCormac J, Meru F, Mordasini C, Osborn A, Pollacco D, Queloz D, Raynard L, Ricker GR, Rowden P, Santerne A, Schlieder JE, Seager S, Sha L, Tan TG, Tilbrook RH, Ting E, Udry S, Vanderspek R, Watson CA, West RG, Wilson PA, Winn JN, Wheatley P, Villasenor JN, Vines JI, and Zhan Z

Abstract

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune 'desert' 1,2 (a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b 3 , which is thought to have an unusually massive core, and recent discoveries such as LTT9779b 4 and NGTS-4b 5 , on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune's but an anomalously large mass of [Formula: see text] Earth masses and a density of [Formula: see text] grams per cubic centimetre, similar to Earth's. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than [Formula: see text] per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation 6 . Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.

Published
2020
Full Text
View/download PDF

49. A planet within the debris disk around the pre-main-sequence star AU Microscopii.

Author

Plavchan P, Barclay T, Gagné J, Gao P, Cale B, Matzko W, Dragomir D, Quinn S, Feliz D, Stassun K, Crossfield IJM, Berardo DA, Latham DW, Tieu B, Anglada-Escudé G, Ricker G, Vanderspek R, Seager S, Winn JN, Jenkins JM, Rinehart S, Krishnamurthy A, Dynes S, Doty J, Adams F, Afanasev DA, Beichman C, Bottom M, Bowler BP, Brinkworth C, Brown CJ, Cancino A, Ciardi DR, Clampin M, Clark JT, Collins K, Davison C, Foreman-Mackey D, Furlan E, Gaidos EJ, Geneser C, Giddens F, Gilbert E, Hall R, Hellier C, Henry T, Horner J, Howard AW, Huang C, Huber J, Kane SR, Kenworthy M, Kielkopf J, Kipping D, Klenke C, Kruse E, Latouf N, Lowrance P, Mennesson B, Mengel M, Mills SM, Morton T, Narita N, Newton E, Nishimoto A, Okumura J, Palle E, Pepper J, Quintana EV, Roberge A, Roccatagliata V, Schlieder JE, Tanner A, Teske J, Tinney CG, Vanderburg A, von Braun K, Walp B, Wang J, Wang SX, Weigand D, White R, Wittenmyer RA, Wright DJ, Youngblood A, Zhang H, and Zilberman P

Abstract

AU Microscopii (AU Mic) is the second closest pre-main-sequence star, at a distance of 9.79 parsecs and with an age of 22 million years 1 . AU Mic possesses a relatively rare 2 and spatially resolved 3 edge-on debris disk extending from about 35 to 210 astronomical units from the star 4 , and with clumps exhibiting non-Keplerian motion 5-7 . Detection of newly formed planets around such a star is challenged by the presence of spots, plage, flares and other manifestations of magnetic 'activity' on the star 8,9 . Here we report observations of a planet transiting AU Mic. The transiting planet, AU Mic b, has an orbital period of 8.46 days, an orbital distance of 0.07 astronomical units, a radius of 0.4 Jupiter radii, and a mass of less than 0.18 Jupiter masses at 3σ confidence. Our observations of a planet co-existing with a debris disk offer the opportunity to test the predictions of current models of planet formation and evolution.

Published
2020
Full Text
View/download PDF

50. A noninteracting low-mass black hole-giant star binary system.

Author

Thompson TA, Kochanek CS, Stanek KZ, Badenes C, Post RS, Jayasinghe T, Latham DW, Bieryla A, Esquerdo GA, Berlind P, Calkins ML, Tayar J, Lindegren L, Johnson JA, Holoien TW, Auchettl K, and Covey K

Abstract

Black hole binary systems with companion stars are typically found via their x-ray emission, generated by interaction and accretion. Noninteracting binaries are expected to be plentiful in the Galaxy but must be observed using other methods. We combine radial velocity and photometric variability data to show that the bright, rapidly rotating giant star 2MASS J05215658+4359220 is in a binary system with a massive unseen companion. The system has an orbital period of ~83 days and near-zero eccentricity. The photometric variability period of the giant is consistent with the orbital period, indicating star spots and tidal synchronization. Constraints on the giant's mass and radius imply that the unseen companion is [Formula: see text] solar masses, indicating that it is a noninteracting low-mass black hole or an unexpectedly massive neutron star., (Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Published
2019
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results