HS Piscium b

Subject: HS Piscium b 6th March 2024, 5:48 am

Quote :: We report the discovery of a hot Jupiter candidate orbiting HS Psc, a K7 (≈0.7 M⊙) member of the ≈130 Myr AB Doradus moving group. Using radial velocities over 4 years from the Habitable-zone Planet Finder spectrograph at the Hobby-Eberly Telescope, we find a periodic signal at Pb=3.986^+0.044_-0.003 d. A joint Keplerian and Gaussian process stellar activity model fit to the RVs yields a minimum mass of mpsini=1.5^+0.6_-0.4 M_Jup. The stellar rotation period is well constrained by the Transiting Exoplanet Survey Satellite light curve (Prot=1.086±0.003 d) and is not an integer harmonic nor alias of the orbital period, supporting the planetary nature of the observed periodicity. HS Psc b joins a small population of young, close-in giant giant planet candidates with robust age and mass constraints and demonstrates that giant planets can either migrate to their close-in orbital separations by 130 Myr or form insitu. Given its membership in a young moving group, HS Psc represents an excellent target for follow-up observations to further characterize this young hot Jupiter, refine its orbital properties, and search for additional planets in the system.