  An accurate and precise Kepler Stellar Properties Catalog is essential for
the interpretation of the Kepler exoplanet survey results. Previous Kepler
Stellar Properties Catalogs have focused on reporting the best-available
parameters for each star, but this has required combining data from a variety
of heterogeneous sources. We present the Gaia-Kepler Stellar Properties
Catalog, a set of stellar properties of 186,301 Kepler stars, homogeneously
derived from isochrones and broadband photometry, Gaia Data Release 2
parallaxes, and spectroscopic metallicities, where available. Our photometric
effective temperatures, derived from $g-K_s$ colors, are calibrated on stars
with interferometric angular diameters. Median catalog uncertainties are 112 K
for $T_{\mathrm{eff}}$, 0.05 dex for $\log g$, 4% for $R_\star$, 7% for
$M_\star$, 13% for $\rho_\star$, 10% for $L_\star$, and 56% for stellar age.
These precise constraints on stellar properties for this sample of stars will
allow unprecedented investigations into trends in stellar and exoplanet
properties as a function of stellar mass and age. In addition, our homogeneous
parameter determinations will permit more accurate calculations of planet
occurrence and trends with stellar properties.
