TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star

<jats:title>ABSTRACT</jats:title> <jats:p>We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based...

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Format: Article
Language:English
Published: Oxford University Press (OUP) 2021
Online Access:https://hdl.handle.net/1721.1/135589
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description <jats:title>ABSTRACT</jats:title> <jats:p>We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of MP = 0.138 ± 0.023 $\rm {M_J}$ (43.9 ± 7.3 $\, M_{\rm \oplus}$), a radius of RP = 0.639 ± 0.013 $\rm {R_J}$ (7.16 ± 0.15 $\, \mathrm{ R}_{\rm \oplus}$), bulk density of $0.65^{+0.12}_{-0.11}$ (cgs), and period $18.38818^{+0.00085}_{-0.00084}$ $\rm {days}$. TOI-257b orbits a bright (V = 7.612 mag) somewhat evolved late F-type star with M* = 1.390 ± 0.046 $\rm {M_{sun}}$, R* = 1.888 ± 0.033 $\rm {R_{sun}}$, Teff = 6075 ± 90 $\rm {K}$, and vsin i = 11.3 ± 0.5 km s−1. Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a ∼71 day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars (∼100) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.</jats:p>
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spelling mit-1721.1/1355892022-10-01T21:32:25Z TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star <jats:title>ABSTRACT</jats:title> <jats:p>We report the discovery of a warm sub-Saturn, TOI-257b (HD 19916b), based on data from NASA’s Transiting Exoplanet Survey Satellite (TESS). The transit signal was detected by TESS and confirmed to be of planetary origin based on radial velocity observations. An analysis of the TESS photometry, the Minerva-Australis, FEROS, and HARPS radial velocities, and the asteroseismic data of the stellar oscillations reveals that TOI-257b has a mass of MP = 0.138 ± 0.023 $\rm {M_J}$ (43.9 ± 7.3 $\, M_{\rm \oplus}$), a radius of RP = 0.639 ± 0.013 $\rm {R_J}$ (7.16 ± 0.15 $\, \mathrm{ R}_{\rm \oplus}$), bulk density of $0.65^{+0.12}_{-0.11}$ (cgs), and period $18.38818^{+0.00085}_{-0.00084}$ $\rm {days}$. TOI-257b orbits a bright (V = 7.612 mag) somewhat evolved late F-type star with M* = 1.390 ± 0.046 $\rm {M_{sun}}$, R* = 1.888 ± 0.033 $\rm {R_{sun}}$, Teff = 6075 ± 90 $\rm {K}$, and vsin i = 11.3 ± 0.5 km s−1. Additionally, we find hints for a second non-transiting sub-Saturn mass planet on a ∼71 day orbit using the radial velocity data. This system joins the ranks of a small number of exoplanet host stars (∼100) that have been characterized with asteroseismology. Warm sub-Saturns are rare in the known sample of exoplanets, and thus the discovery of TOI-257b is important in the context of future work studying the formation and migration history of similar planetary systems.</jats:p> 2021-10-27T20:24:09Z 2021-10-27T20:24:09Z 2021 2021-09-27T17:47:17Z Article http://purl.org/eprint/type/JournalArticle https://hdl.handle.net/1721.1/135589 en 10.1093/MNRAS/STAA3960 Monthly Notices of the Royal Astronomical Society Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf Oxford University Press (OUP) arXiv
spellingShingle TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
title TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
title_full TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
title_fullStr TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
title_full_unstemmed TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
title_short TOI-257b (HD 19916b): A Warm sub-Saturn Orbiting an Evolved F-type Star
title_sort toi 257b hd 19916b a warm sub saturn orbiting an evolved f type star
url https://hdl.handle.net/1721.1/135589