FIRST LIGHT CURVE ANALYSIS OF THE MODERATE FILL-OUT CONTACT BINARY SYSTEMS TYC 2402-643-1, TYC 2703-1235-1 AND TYC 2913-2145-1

Abstract

We present the results of our study of the W Ursae Majoris eclipsing binary systems (EW) TYC 2402-643-1, TYC 2703-1235-1 and TYC 2913-2145-1 based on CCD observations obtained using Sloan g’ and i' filters. The light curves were analysed using the latest version of the Wilson-Devinney code, and the obtained data were used to estimate the physical parameters of the systems. TYC 2402-643-1 and TYC 2913-2145-1, having mass ratio < 0.25, can be classified as Extreme Mass Ratio Binary (EMRBs) systems and belong to the A-subtype class of the EW. The third one, TYC 2703-1235-1, having mass ratio q about 3 (1/q = 0.33) belongs to W-subtype class of the EW. The absolute dimensions of the primaries and secondaries were estimated and investigated using different evolutionary diagrams. The parameters of the progenitors of the components of the systems were calculated and the results are consistent with the determination of the subtypes.