KOI planets and KIC stars from Kepler DR25

By combining information on stellar elemental abundances and kinematics, we constructed separate samples of Kepler stars according to their affiliation to the Galactic components of thin disc, thick disc, and stellar halo. Using a Bayesian analysis with conjugate priors, we then investigated how planet occurrence rates differ in different regions of planet properties.

We find that young, slow, and metal-rich stars, associated mainly with the thin disc, host on average more planets (especially close-in super Earths) compared to the old, fast, and metal-poor thick disc stars. We further assess the dependence between stellar properties such as spectral type and metallicity, and planet occurrence rates. The trends we find agree with those found by other authors as well.