The Kepler Mission revolutionized exoplanet science and stellar astrophysics by obtaining highly precise photometry of over 200000 stars over 4yr. A critical piece of information to exploit Kepler data is its selection function, since all targets had to be selected from a sample of half a million stars on the Kepler CCDs using limited information. Here we use Gaia DR2 to reconstruct the Kepler selection function and explore possible biases with respect to evolutionary state, stellar multiplicity, and kinematics. We find that the Kepler target selection is nearly complete for stars brighter than Kp<14mag and was effective at selecting main-sequence stars, with the fraction of observed stars decreasing from 95% to 60% between 14<Kp1.2) RUWE values at ~{sigma} significance, suggesting that the Kepler target selection shows some bias against either close or wide binaries. We furthermore use the Gaia proper motions to show that the Kepler selection function was unbiased with respect to kinematics.

Cone search capability for table J/AJ/161/231/table1 (Stellar properties of all stars that fall on the Kepler CCDs)