TOI-1259Ab – a gas giant planet with 2.7 per cent deep transits and a bound white dwarf companion

Research output: Contribution to journalArticlepeer-review


  • David V. Martin
  • Kareem El-Badry
  • Vedad Kunovac Hodžić
  • Ruth Angus
  • Jessica Birky
  • Daniel Foreman-Mackey
  • Christina Hedges
  • Benjamin T. Montet
  • Simon J. Murphy
  • Alexandre Santerne
  • Keivan G. Stassun
  • Alexander P. Stephan
  • Ji Wang
  • Paul Benni
  • Vadim Krushinsky
  • Nikita Chazov
  • Nikolay Mishevskiy
  • Carl Ziegler
  • Abderahmane Soubkiou
  • Zouhair Benkhaldoun
  • Douglas A. Caldwell
  • Karen Collins
  • Christopher E. Henze
  • Natalia M. Guerrero
  • Jon M. Jenkins
  • David W. Latham
  • Adam Levine
  • Scott McDermott
  • Susan E. Mullally
  • George Ricker
  • Sara Seager
  • Avi Shporer
  • Andrew Vanderburg
  • Roland Vanderspek
  • Joshua N. Winn

Colleges, School and Institutes


We present TOI-1259Ab, a 1.0 Rjup gas giant planet transiting a 0.71 R K-dwarf on a 3.48 day orbit. The system also contains a bound white dwarf companion TOI-1259B with a projected distance of approximately 1600 AU from the planet host. Transits are observed in nine TESS sector 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 ms-1, implying a planet mass of 0.44 Mjup. 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 a rotational variability with a period of 28 days, which implies a gyrochronology age broadly consistent with the white dwarf's total age.

Bibliographic note

Final Version of Record not yet available as of 04/08/2021. Accepted to MNRAS. Some structural changes from first arXiv version but no significant changes to results. One figure got a bit prettier


Original languageEnglish
JournalMonthly Notices of the Royal Astronomical Society
Early online date27 Jul 2021
Publication statusE-pub ahead of print - 27 Jul 2021


  • astro-ph.EP, astro-ph.SR