TOI-503: The First Known Brown-dwarf Am-star Binary from the TESS Mission

0534667 - ASÚ 2021 RIV US eng J - Journal Article
Šubjak, Ján - Sharma, R. - Carmichael, T.W. - Johnson, M. C. - Gonzales, E. J. - Matthews, E. - Boffin, H.M.J. - Brahm, R. - Chaturvedi, P. - Chakraborty, A. - Blažek, Martin - Skarka, Marek - Kabáth, Petr - Špoková, Magdaléna … Total 81 authors
TOI-503: The First Known Brown-dwarf Am-star Binary from the TESS Mission.
Astronomical Journal. Roč. 159, č. 4 (2020), č. článku 151. ISSN 0004-6256. E-ISSN 1538-3881
R&D Projects: GA ČR(CZ) GC17-01752J
Institutional support: RVO:67985815
Keywords : brown dwarfs * stellar ages * Am stars
OECD category: Astronomy (including astrophysics,space science)
Impact factor: 6.281, year: 2020
Method of publishing: Limited access
https://doi.org/10.3847/1538-3881/ab7245

We report the discovery of an intermediate-mass transiting brown dwarf (BD), TOI-503b, from the TESS mission. TOI-503b is the first BD discovered by TESS, and it has circular orbit around a metallic-line A-type star with a period of P.=.3.6772.+/-.0.0001 days. The light curve from TESS indicates that TOI-503b transits its host star in a grazing manner, which limits the precision with which we measure the BD's radius ( = R 1.34+ R b 0.150.26 J). We obtained highresolution spectroscopic observations with the FIES, Ondr.ejov, PARAS, Tautenburg, and TRES spectrographs, and measured the mass of TOI-503b to be Mb.=.53.7.+/-.1.2 MJ. The host star has a mass of Ma.=.1.80.+/-.0.06Me, a radius of Ra.=.1.70.+/-.0.05Re, an effective temperature of Teff.=.7650.+/-.160 K, and a relatively high metallicity of 0.61.+/-.0.07 dex. We used stellar isochrones to derive the age of the system to be 180 Myr, which places its age between that of RIK 72b (a 10 Myr old BD in the Upper Scorpius stellar association) and AD 3116b (a 600 Myr old BD in the Praesepe cluster).
Permanent Link: http://hdl.handle.net/11104/0312837