Stellar Limb-Darkening Coefficients for CoRot and Kepler

TL;DR

This paper provides limb-darkening coefficients for CoRot and Kepler missions using stellar atmospheric models, improving the fit to observed transiting exoplanet lightcurves by addressing limb model deficiencies.

Contribution

It introduces a new method for calculating limb-darkening coefficients that better matches observed data by excluding limb intensities, enhancing stellar modeling accuracy.

Findings

Better fits achieved when two limb intensities are excluded

LDCs cover a wide range of stellar parameters

Method reduces deficiencies in 1D stellar models

Abstract

Transiting exoplanets provide unparalleled access to the fundamental parameters of both extrasolar planets and their host stars. We present limb-darkening coefficients (LDCs) for the exoplanet hunting CoRot and Kepler missions. The LDCs are calculated with ATLAS stellar atmospheric model grids and span a wide range of Teff, log g, and metallically [M/H]. Both CoRot and Kepler contain wide, nonstandard response functions, and are producing a large inventory of high-quality transiting lightcurves, sensitive to stellar limb darkening. Comparing the stellar model limb darkening to results from the first seven CoRot planets, we find better fits are found when two model intensities at the limb are excluded in the coefficient calculations. This calculation method can help to avoid a major deficiency present at the limbs of the 1D stellar models.