Presentation #339.01 in the session Exoplanet Transits II.
Hot Jupiters are generally observed to lack close planetary companions, a trend that has been interpreted as evidence for high-eccentricity migration. We present the discovery and validation of TOI-822.02, a 1.78 ± 0.10 REarth planet on a 1.01 day orbit interior to the hot Jupiter WASP-132 b. Transiting Exoplanet Survey Satellite (TESS) and ground-based follow-up observations, in conjunction with vetting and validation analysis, enable us to rule out common astrophysical false positives and validate the observed transit signal produced by TOI-822.02 as a planet, dubbed here as WASP-132 c. Running the validation tools VESPA and TRICERATOPS on this signal yield false positive probabilities of 9×10-5 and 0.0107, respectively. Analysis of archival CORALIE radial velocity data leads to a 3s upper limit of 24.7 ms-1 on the amplitude of any 1.01-day signal, corresponding to a 3s upper mass limit of 32.65 MEarth. Dynamical simulations reveal that the system is stable within the 3s uncertainties on planetary and orbital parameters for timescales of ~100 Myr. The existence of a planetary companion near the hot Jupiter WASP-132 b makes the giant planet’s formation and evolution via high-eccentricity migration highly unlikely. Being one of just a handful of nearby planetary companions to hot Jupiters, WASP-132 c carries with it significant implications for the formation of the system and hot Jupiters as a population. We present this result in the context of our ongoing uniform search for additional planets around all stars with confirmed hot Jupiters that have been observed by TESS. This includes a refined estimate of the occurrence rate of small companion planets nearby hot Jupiters, a value that has implications for the formation of hot Jupiters on a population level.