Abstract
We report on the discovery and validation of TOI 813 b (TIC 55525572 b),
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\star - 1.94 R⊙,
M\star = 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
83.8911-0.0031+0.0027 d, a planet radius of 6.71
± 0.38 R⊕ and a semimajor axis of
0.423-0.037+0.031 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.
Original language | English |
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Pages (from-to) | 750-763 |
Journal | Monthly Notices of the Royal Astronomical Society |
Volume | 494 |
Issue number | 1 |
Early online date | 23 Jan 2020 |
DOIs | |
Publication status | Published - 01 May 2020 |
Keywords
- methods: statistical
- planets and satellites: detection
- stars: fundamental parameters
- stars: individual (TIC-55525572
- TOI 813)