SOLAR-TYPE ECLIPSING BINARY KIC 4832197: PHYSICAL PROPERTIES AND INTRINSIC VARIABILITY OF THE COMPONENTS

Abstract

Comprehensive analysis of optical spectroscopy and space photometry of the solar type eclipsing binary system KIC 4832197 is presented. The system is composed of F7V + F9V components with masses of M1 = 1.16 ± 0.12 M☉, M2 = 1.07 ± 0.10 M☉ and radii of R1 = 1.26 ± 0.04 R☉, R2 = 1.03 ± 0.03 R☉. The position of the components on the Log Teff – Log L/L☉ plane suggests an age of 2.8 ± 0.8 Gyr for the system. Inspection of out-of-eclipse brightness in time reveals a wave-like variability pattern, whose amplitude and shape quickly change on order of days. Frequency analysis of this variability results in two significant peaks in the amplitude spectrum, which are interpreted as rotational modulation of spots on the components. Assuming both spots are on the same component, a lower limit for the differential rotation coeffcient is computed as k = 0.12, which is weaker compared to the solar value of k☉ = 0.189.