Alison Duck (JPL): "Systematic Uncertainties in Transiting Exoplanets and Their Host Stars"

Transiting exoplanet systems offer a unique opportunity to measure precise masses and radii of planets and their host stars. However, relative photometry and radial velocity measurements alone only constrain the host star density, leaving a one-parameter mass-radius degeneracy. I assess the magnitude of systematic errors in the derived system parameters relative to their statistical precision due to different methods of breaking this degeneracy. First, I model extant data for the typical hot Jupiter system KELT-15 using EXOFASTv2, considering four methods of stellar characterization. Next, I apply similar techniques to precisely characterize M-dwarfs in binaries with FGK primary stars as they are important hosts of many Earth-sized planets. Finally, I leverage a sample of 8 TESS transiting systems with secondary eclipse observations to place constraints on the average population bond albedo, heat recirculation efficiency, and orbital eccentricity to recover demographic trends in hot Jupiters using only the TESS band-pass. Soon, NASA’s Nancy Grace Roman Space Telescope will lead to a paradigm shift by discovering an estimated 100,000 transiting planets. Here, the limiting factor will be our understanding of these faint host stars. I present updates from the working group to characterize these host stars and their transiting planets with quantified systematic uncertainties which will enable exoplanet demographic studies across host star properties and galactic position with the largest population of exoplanets ever observed.