Presentation #102.325 in the session Poster Session.
The magnetic activity of host stars is a key factor driving planet formation and evolution, and the long-term sustainability of temperate planetary surface conditions, and may explain how planet radius as a function of orbital period reveals distinct populations of planets beyond the bifurcation of super-earths and mini-neptunes. We thus explore chromospheric activity trends for planetary populations including those in the hot-neptune desert, the radius gap and at ultra-short orbital periods. Using uniformly collected high-resolution spectra of Kepler planet-host stars from the Keck I telescope and HIRES instrument, we analyze exoplanet properties as a function of chromospheric activity as measured by the Ca II H&K lines. Using well-determined stellar properties from the California Kepler Survey, including stellar and corresponding planetary radii with errors of less than 5%, we search for correlations between planet properties and a variety of activity metrics. The planet radius gap has been shown to be influenced by stellar insolation, informing theories such as core-accretion and photo-evaporation, and setting the timescales relevant for forming mini-neptunes and super-earths. Our stellar activity results complement that of the California Kepler Survey, which presents fundamental stellar properties of ~1000 planet hosting stars.