Photometric Stellar Parameters for 195,478 Kepler Input Catalog (KIC) Stars

TL;DR

This study provides accurate photometric stellar parameters for nearly all stars in the Kepler Input Catalog, enabling improved characterization for exoplanet and stellar research.

Contribution

It introduces a method to estimate stellar parameters for over 195,000 KIC stars using photometric data and spectroscopic relationships, covering 97% of the catalog.

Findings

Achieved 0.1 dex metallicity accuracy

Estimated stellar ages with 20% precision for turn-off stars

Determined stellar masses and radii with high accuracy

Abstract

The stellar atmospheric parameters and physical properties of stars in the Kepler Input Catalog (KIC) are of great significance for the study of exoplanets, stellar activity, and asteroseismology. However, despite extensive effort over the past decades, accurate spectroscopic estimates of these parameters are available for only about half of the stars in the full KIC catalog. In our work, by training relationships between photometric colors and spectroscopic stellar parameters from Gaia DR3, the Kepler Issac-Newton Survey, LAMOST DR10, and APOGEE DR17, we have obtained atmospheric-parameter estimates for over 195,000 stars, accounting for 97$\%$ of the total sample of KIC stars. We obtain 1$\sigma$ uncertainties of 0.1 dex on metallicity [Fe/H], 100 K on effective temperature $T_{\rm eff}$, and 0.2 dex on surface gravity log $g$. In addition, based on these atmospheric parameters, we estimated the ages, masses, radii, and surface gravities of these stars using the commonly adopted isochrone-fitting approach. External comparisons indicate that the resulting precision for turn-off stars is 20$\%$ in age; for dwarf stars, it is 0.07 $M_{\odot}$ in mass, 0.05 $R_{\odot}$ in radius, and 0.12 dex in surface gravity; and for giant stars, it is 0.14 $M_{\odot}$ in mass, 0.73 $R_{\odot}$ in radius, and 0.11 dex in surface gravity.