The TESS Grand Unified Hot Jupiter Survey

Abstract

Hot Jupiters – gas giant planets that orbit their stars once every few days – were a surprising discovery at the dawn of the exoplanet era. The existence of these massive planets so close to their host stars contradicted previous theories of planet formation, and their origins remain unclear. Even though hundreds of hot Jupiters have now been found, the sample was drawn from a diverse collection of ground-based surveys with heterogeneous selection biases, making it difficult to draw statistical inferences about this population.This dissertation presents the TESS Grand Unified Hot Jupiter Survey – our effort to leverage NASA’s Transiting Exoplanet Survey Satellite (TESS) to expand the statistical sample of hot Jupiters by an order of magnitude. By uniformly searching the sky for transiting exoplanets, TESS allows us to unify the past three decades of ground-based planet searches with new discoveries, thereby assembling a homogeneous catalog of 400 transiting hot Jupiters orbiting FGK stars brighter than G ≤ 12.5. Chapter 2 contains our initial forecasts and feasibility study for this survey, where we found that ≈ 50% of hot Jupiters around such a sample of stars remained to be discovered. Chapters 3 through 5 describe the discovery of 60 new giant planets from our survey, based on follow-up photometric, imaging, and spectroscopic data. These observations are key to confirming the planet candidates from TESS and eliminating false positives. We highlight the first statistical findings to emerge from our survey in Chapter 6, where we show that the orbital period distribution of hot Jupiters does not depend the metallicity of their host stars. Looking forward, we present an update on the current status of the survey in Chapter 7, including new planet confirmations, a list of false positives, and a preliminary magnitude-limited catalog of hot Jupiters. Finally, in Chapter 8, we provide a glimpse at the demographic results from the full sample, including a 4-σ detection of the “period pile-up” at ≈ 3 days, and quantifying how hot Jupiter occurrence rates depend on stellar metallicity. These are the first clues toward understanding the enigmatic origins of hot Jupiters.