Spectroscopy of TOI-1259B – an unpolluted white dwarf companion to an inflated warm Saturn

• DOI: 10.1093/mnras/stac2879
• Publication Date: 2022-10-07T20:41:00Z
• Authors: Evan Fitzmaurice; David V Martin; Romy Rodríguez Ma...; Patrick Vallely; Alexander P Stephan; Kiersten M Boley; Rick Pogge; Kareem El-Badry; Vedad Kunovac; Amaury H M J Triaud
• Keywords: William Herschel Telescope; Black dwarf

TOI-1259 consists of a transiting exoplanet orbiting main sequence star, with bound outer white dwarf companion. Less than dozen systems this architecture are known. We conduct follow-up spectroscopy on the TOI-1259B using Large Binocular Telescope (LBT) to better characterise it. observe only strong hydrogen lines, making DA dwarf. see no evidence heavy element pollution, which would have been planetary material around Such pollution is seen in ~ 25 - 50% dwarfs, but it unknown if rate higher or lower TOI-1259-like that contain known planet. Our permits an improved age measurement 4.05 (+1.00 -0.42) Gyrs, matches gyrochronology star. This first expanded sample similar binaries will allow us calibrate these dating methods and provide new perspective planets binaries.