An Eccentric Massive Jupiter Orbiting a Subgiant on a 9.5-day Period Discovered in the Transiting Exoplanet Survey Satellite Full Frame Images

Abstract

We report the discovery of TOI-172 b from the Transiting Exoplanet Survey Satellite ( TESS ) mission, a massive hot Jupiter transiting a slightly evolved G star with a 9.48-day orbital period. This is the first planet to be confirmed from analysis of only the TESS full frame images, because the host star was not chosen as a two-minute cadence target. From a global analysis of the TESS photometry and follow-up observations carried out by the TESS Follow-up Observing Program Working Group, TOI-172 (TIC 29857954) is a slightly evolved star with an effective temperature of T eff  = 5645 ± 50 K, a mass of M ⋆  =  M ⊙ , radius of R ⋆  =  R ⊙ , a surface gravity of log g ⋆  =  , and an age of . Its planetary companion (TOI-172 b) has a radius of R P  =  R J , a mass of M P  =  M J , and is on an eccentric orbit ( ). TOI-172 b is one of the few known massive giant planets on a highly eccentric short-period orbit. Future study of the atmosphere of this planet and its system architecture offer opportunities to understand the formation and evolution of similar systems.