FUNDAMENTAL PARAMETERS OF KEPLER ECLIPSING BINARIES. I. KIC 5738698

Abstract

Eclipsing binaries serve as a valuable source of stellar masses and radii that inform stellar evolutionary models and provide insight into additional astrophysical processes. The exquisite light curves generated by space-based missions such as Kepler offer the most stringent tests to date. We use the Kepler light curve of the 4.8 day eclipsing binary KIC 5739896 with ground based optical spectra to derive fundamental parameters for the system. We reconstruct the component spectra to determine the individual atmospheric parameters, and model the Kepler photometry with the binary synthesis code Eclipsing Light Curve to obtain accurate masses and radii. The two components of KIC 5738698 are F-type stars with M 1 = 1.39 ± 0.04 M ⊙ , M 2 = 1.34 ± 0.06 M ⊙ , and R 1 = 1.84 ± 0.03 R ⊙ , R 2 = 1.72 ± 0.03 R ⊙ . We also report a small eccentricity ( e ≲ 0.0017 ) and unusual albedo values that are required to match the detailed shape of the Kepler light curve. Comparison with evolutionary models indicate an approximate age of 2.3 Gyr for the system.