Better Stars, Better Planets: Exploiting the Stellar-Exoplanetary Synergy

Coordinators: Rebekah Dawson, Jim Fuller, Daniel Huber, Katja Poppenhaeger, and Victor Silva Aguirre

Scientific Advisors: Eric Agol and Joshua Winn

Understanding stars is crucial to characterizing exoplanets. The revolutionary results of the Kepler mission have required the expertise of both the exoplanet and stellar communities to characterize these new worlds, including measuring precise planetary radii and host star chemical composition, studying the dynamical architectures of exoplanet systems, and understand how stellar variability and magnetic activity affect exoplanet detection efficiencies. Despite these strong synergies, the exoplanet and stellar communities have so far largely worked in parallel, with only a small number of conferences dedicated to bring together experts in both fields. As a result, it has not been clear to stellar astrophysicists which stellar characteristics are most essential for understanding the formation, dynamics, and properties of exoplanets, or to exoplanet experts which stellar characterization resources are available and what degeneracies and pitfalls exist in employing stellar properties derived from different methods.

In this program we aim to bring together experts in exoplanet science and stellar astrophysics to foster the unique synergy between these fields and capitalize on two powerful upcoming datasets. The launch of the TESS mission will continue the space-photometry revolution initiated by Kepler, providing near all-sky high-precision photometry to detect transiting exoplanets as well as to study stellar activity, rotation and stellar pulsations (asteroseismology). In parallel, precise astrometric data by Gaia will revolutionize our understanding of stellar populations targeted by Kepler and TESS. The combined datasets will allow us to answer key questions such as: What is the occurrence rate of Earth-sized planets as a function of the properties of the host star such as mass, age, or evolutionary state? What is the influence of stellar activity on exoplanets? How do the dynamical properties of exoplanets (such as mutual inclinations and orbital eccentricities) depend on the stellar environment and vary with stellar age? This KITP program will provide a framework to connect the exoplanet and stellar communities and answer these fundamental questions with the next generation of space-based data.