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Author Bergmann, C.; Jones, MI.; Zhao, J.; Mustill, AJ.; Brahm, R.; Torres, P.; Wittenmyer, RA.; Gunn, F.; Pollard, KR.; Zapata, A.; Vanzi, L.; Wang, SH.
Title HD 76920 b pinned down: A detailed analysis of the most eccentric planetary system around an evolved star Type
Year 2021 Publication Publications of the Astronomical Society of Australia Abbreviated Journal PUBL. ASTRON. SOC. AUST.
Volume 38 Issue Pages e019
Abstract We present 63 new multi-site radial velocity (RV) measurements of the K1III giant HD 76920, which was recently reported to host the most eccentric planet known to orbit an evolved star. We focused our observational efforts on the time around the predicted periastron passage and achieved near-continuous phase coverage of the corresponding RV peak. By combining our RV measurements from four different instruments with previously published ones, we confirm the highly eccentric nature of the system and find an even higher eccentricity of , an orbital period of 415.891(-0.039)(+0.043) d, and a minimum mass of 3.13(-0.43)(+0.41) M-J for the planet. The uncertainties in the orbital elements are greatly reduced, especially for the period and eccentricity. We also performed a detailed spectroscopic analysis to derive atmospheric stellar parameters, and thus the fundamental stellar parameters (M-*, R-*, L-*) taking into account the parallax from Gaia DR2, and independently determined the stellar mass and radius using asteroseismology. Intriguingly, at periastron, the planet comes to within 2.4 stellar radii of its host star's surface. However, we find that the planet is not currently experiencing any significant orbital decay and will not be engulfed by the stellar envelope for at least another 50-80 Myr. Finally, while we calculate a relatively high transit probability of 16%, we did not detect a transit in the TESS photometry.
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1323-3580 ISBN Medium
Area Expedition Conference
Notes WOS:000642222500001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1379
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Author Bouma, L.G.; Hartman, J.D.; Brahm, R.; Evans, P.; Collins, K.A.; Zhou, G.; Sarkis, P.; Quinn, S.N.; de Leon, J.; Livingston, J.; Bergmann, C.; Stassun, K.G.; Bhatti, W.; Winn, J.N.; Bakos, G.A.; Abe, L.; Crouzet, N.; Dransfield, G.; Guillot, T.; Marie-Sainte, W.; Mekarnia, D.; Triaud, A.H.M.J.; Tinney, C.G.; Henning, T.; Espinoza, N.; Jordan, A.; Barbieri, M.; Nandakumar, S.; Trifonov, T.; Vines, J.I.; Vuckovic, M.; Ziegler, C.; Law, N.; Mann, A.W.; Ricker, G.R.; Vanderspek, R.; Seager, S.; Jenkins, J.M.; Burke, C.J.; Dragomir, D.; Levine, A.M.; Quintana, E.V.; Rodriguez, J.E.; Smith, J.C.; Wohler, B.
Title Cluster Difference Imaging Photometric Survey. II. TOI 837: A Young Validated Planet in IC 2602 Type
Year 2020 Publication Astronomical Journal Abbreviated Journal Astron. J.
Volume 160 Issue 5 Pages 20 pp
Abstract We report the discovery of TOI 837b and its validation as a transiting planet. We characterize the system using data from the NASA Transiting Exoplanet Survey Satellite mission, the ESA Gaia mission, ground-based photometry from El Sauce and ASTEP400, and spectroscopy from CHIRON, FEROS, and Veloce. We find that TOI 837 is a T = 9.9 mag G0/F9 dwarf in the southern open cluster IC 2602. The star and planet are therefore 35(-5)(+11) million years old. Combining the transit photometry with a prior on the stellar parameters derived from the cluster color-magnitude diagram, we find that the planet has an orbital period of 8.3 days and is slightly smaller than Jupiter (R-p = 0.77(0.07)(+0.09) R-Jup). From radial velocity monitoring, we limit M-p sin i to less than 1.20 M-Jup (3 sigma). The transits either graze or nearly graze the stellar limb. Grazing transits are a cause for concern, as they are often indicative of astrophysical false-positive scenarios. Our follow-up data show that such scenarios are unlikely. Our combined multicolor photometry, high-resolution imaging, and radial velocities rule out hierarchical eclipsing binary scenarios. Background eclipsing binary scenarios, though limited by speckle imaging, remain a 0.2% possibility. TOI 837b is therefore a validated adolescent exoplanet. The planetary nature of the system can be confirmed or refuted through observations of the stellar obliquity and the planetary mass. Such observations may also improve our understanding of how the physical and orbital properties of exoplanets change in time.
Address [Bouma, L. G.; Hartman, J. D.; Bhatti, W.; Winn, J. N.; Bakos, G. A.] Princeton Univ, Dept Astrophys Sci, 4 Ivy Lane, Princeton, NJ 08540 USA, Email: luke@astro.princeton.edu
Corporate Author Thesis
Publisher Iop Publishing Ltd Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0004-6256 ISBN Medium
Area Expedition Conference
Notes WOS:000585065500001 Approved
Call Number UAI @ alexi.delcanto @ Serial 1260
Permanent link to this record