<i>KEPLER</i>INPUT CATALOG: PHOTOMETRIC CALIBRATION AND STELLAR CLASSIFICATION

Abstract

We describe the photometric calibration and stellar classification methods\nused to produce the Kepler Input Catalog (KIC). The KIC is a catalog containing\nphotometric and physical data for sources in the Kepler Mission field of view;\nit is used by the mission to select optimal targets. We derived atmospheric\nextinction corrections from hourly observations of secondary standard fields\nwithin the Kepler field of view. Repeatability of absolute photometry for stars\nbrighter than magnitude 15 is typically 2%. We estimated stellar parameters\nTeff, log(g), log (Z), E_{B-V} using Bayesian posterior probability\nmaximization to match observed colors to Castelli stellar atmosphere models. We\napplied Bayesian priors describing the distribution of solar-neighborhood stars\nin the color-magnitude diagram (CMD), in log (Z)$, and in height above the\ngalactic plane. Comparisons with samples of stars classified by other means\nindicate that in most regions of the CMD, our classifications are reliable\nwithin about +/- 200 K and +/- 0.4 dex in log (g). It is difficult to assess\nthe reliability of our log(Z) estimates, but there is reason to suspect that it\nis poor, particularly at extreme Teff. Of great importance for the Kepler\nMission, for Teff &lt;= 5400 K, the distinction between main-sequence stars and\ngiants has proved to be reliable with better than 98% confidence. The KIC is\navailable through the MAST data archive.\n