TOI-1259Ab – a gas giant planet with 2.7 per cent deep transits and a bound white dwarf companion. Issue 3 (27th July 2021)

• Record Type: Journal Article
• Authors: Martin, David V; El-Badry, Kareem; Hodžić, Vedad Kunovac; Triaud, Amaury H M J; Angus, Ruth; Birky, Jessica; Foreman-Mackey, Daniel; Hedges, Christina; Montet, Benjamin T; Murphy, Simon J; Santerne, Alexandre; Stassun, Keivan G; Stephan, Alexander P; Wang, Ji; Benni, Paul; Krushinsky, Vadim; Chazov, Nikita; Mishevskiy, Nikolay; Ziegler, Carl; Soubkiou, Abderahmane; Benkhaldoun, Zouhair; Boisse, Isabelle; Battley, Matthew; Miller, Nicola J; Caldwell, Douglas A; Collins, Karen; Henze, Christopher E; Guerrero, Natalia M; Jenkins, Jon M; Latham, David W; Levine, Adam; McDermott, Scott; Mullally, Susan E; Ricker, George; Seager, Sara; Shporer, Avi; Vanderburg, Andrew; Vanderspek, Roland; Winn, Joshua N;
• Is Part Of: Monthly notices of the Royal Astronomical Society. Volume 507:Issue 3(2021)
• Page Start: 4132
• Page End: 4148
• Publication Date: 2021-07-27
• Subjects: planets and satellites: formation -- binaries: eclipsing -- stars: individual (TOI-1259) -- stars: low-mass -- stars: rotation; Astronomy -- Periodicals; Periodicals; 520.5
• DOI: 10.1093/mnras/stab2129
• Languages: English
• ISSNs: 0035-8711

Abstract

ABSTRACT: We present TOI-1259Ab, a 1.0 R Jup gas giant planet transiting a 0.71 R ⊙ K-dwarf on a 3.48 d orbit. The system also contains a bound white dwarf companion TOI-1259B with a projected distance of ∼1600 au from the planet host. Transits are observed in nine TESS sectors and are 2.7 per cent deep – among the deepest known – making TOI-1259Ab a promising target for atmospheric characterization. Our follow-up radial velocity measurements indicate a variability of semiamplitude $K=71\, \rm m\, s^{-1}$, implying a planet mass of 0.44 M Jup . By fitting the spectral energy distribution of the white dwarf, we derive a total age of $4.08^{+1.21}_{-0.53}$ Gyr for the system. The K dwarf's light curve reveals rotational variability with a period of 28 d, which implies a gyrochronology age broadly consistent with the white dwarf's total age.