First R and I Lights and Their Photometric Analyses of GSC 02393–00680

Abstract

Abstract We obtained complete $R$ and $I$ light curves of GSC 02393$-$00680 in 2008 and analyzed them with the 2003 version of the W–D code. It has been shown that GSC 02393$-$00680 is a W-type shallow contact binary system with a high mass ratio, $q =$ 1.600, and a degree of contact factor, $f =$ 5.0% ($\pm$1.3%). It will be a good example to check up on the TRO theory. A period investigation based on all available data suggests that the system has a small-amplitude period oscillation ($A_3 =$ 0$.^{\rm d}$0030; $T_3 =$ 1.92 years). This may indicate that it has a moderate-mass close third body, which is similar to XY Leo.