Light-time effect in the eclipsing binary system AM Leonis

Abstract

We report four new times of minimum light and the improved ephemeris for the well known contact binary AM Leo. The O-C diagram, constructed with all reliable timings found in the literature was analyzed and the the light-time effect in the system was confirmed. We found a periodicity of 44.82 years in the O-C residuals with an amplitude of 0.0058 day. The periodic curve representing the O-C values is asymmetric indicating a large eccentricity of 0.73 of the third body orbit. The mass of the third body is found to be 0.175 M-circle dot for the orbital inclination of the eclipsing pair's orbit.