Planet Hunters Tess I: TOI 813, a subgiant hosting a transiting Saturn-sized planet on an 84-day orbit
Review article, 2020
We report on the discovery and validation of TOI 813 b (TIC55525572b), a transiting exoplanet identified by citizen scientists in data from NASA's Transiting Exoplanet Survey Satellite (TESS) and the first planet discovered by the Planet Hunters TESS project. The host star is a bright (V = 10.3 mag) subgiant (R* = 1.94 R☉, M☉ = 1.32 M☉). It was observed almost continuously by TESS during its first year of operations, during which time four individual transit events were detected. The candidate passed all the standard light curve-based vetting checks, and ground-based follow-up spectroscopy and speckle imaging enabled us to place an upper limit of 2 MJup (99 per cent confidence) on the mass of the companion, and to statistically validate its planetary nature. Detailed modelling of the transits yields a period of 83.8911+0.0027-0.0031 d, a planet radius of 6.71 ± 0.38 R⊕ and a semimajor axis of 0.423+0031-0.037 AU. The planet's orbital period combined with the evolved nature of the host star places this object in a relatively underexplored region of parameter space. We estimate that TOI 813 b induces a reflex motion in its host star with a semi-amplitude of ∼6 m s−1, making this a promising system to measure the mass of a relatively long-period transiting planet.
Stars: fundamental parameters
Stars: individual (TIC-55525572 - TOI 813)
Methods: statistical
Planets and satellites: detection
Author
N. L. Eisner
University of Oxford
O. Barragán
University of Oxford
S. Aigrain
University of Oxford
C. Lintott
University of Oxford
G. Miller
University of Oxford
N. Zicher
University of Oxford
T. S. Boyajian
Louisiana State University
C. Briceño
Cerro Tololo Inter American Observatory
E. Bryant
The University of Warwick
J. L. Christiansen
NASA Ames Research Center
A. D. Feinstein
University of Chicago
L. M. Flor-Torres
Universidad de Guanajuato
Malcolm Fridlund
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Leiden University
D. Gandolfi
University of Turin
J. Gilbert
Australian National University
N. Guerrero
Massachusetts Institute of Technology (MIT)
Jon M. Jenkins
NASA Ames Research Center
K. Jones
University of Oxford
M. H. Kristiansen
Technical University of Denmark (DTU)
A. Vanderburg
The University of Texas at Austin
N. Law
The University of North Carolina System
A. R. López-Sánchez
Macquarie University
Australian Astronomical Optics
A. Mann
The University of North Carolina System
E. J. Safron
Louisiana State University
M. E. Schwamb
Queen's University Belfast
Gemini Observatory North
Keivan G. Stassun
Vanderbilt University
Fisk University
H. P. Osborn
Laboratoire d'Astrophysique de Marseille
J. Wang
Yale University
A. Zic
Commonwealth Scientific and Industrial Research Organisation (CSIRO)
The University of Sydney
C. Ziegler
University of Toronto
F. Barnet
Zooniverse
S. J. Bean
Zooniverse
D. M. Bundy
Zooniverse
Z. Chetnik
Zooniverse
J. L. Dawson
Zooniverse
J. Garstone
Zooniverse
A. G. Stenner
Zooniverse
M. Huten
Zooniverse
S. Larish
Zooniverse
L. D. Melanson
Zooniverse
T. Mitchell
Zooniverse
C. Moore
Zooniverse
K. Peltsch
Zooniverse
D. J. Rogers
Zooniverse
C. Schuster
Zooniverse
D. S. Smith
Zooniverse
D. J. Simister
Zooniverse
C. Tanner
Zooniverse
I. Terentev
Zooniverse
A. Tsymbal
Zooniverse
Monthly Notices of the Royal Astronomical Society
0035-8711 (ISSN) 1365-2966 (eISSN)
Vol. 494 1 750-763Subject Categories
Subatomic Physics
Astronomy, Astrophysics and Cosmology
Geophysics
DOI
10.1093/mnras/staa138