New Photometric Investigation of the G-Type Contact Binary GSC 0763-0572

We present new CCD photometric light curves of the W UMa-type binary system GSC 0763-0572 in the V, R, and I bands. Here, the light curves in the R and I bands are the first to be obtained. The primary component of this system belongs to a G-type solar-like star; our new observation indicates that the activities of GSC 0763-0572 may be stable. Based on all available times of the light minimum, we found that the orbital period is variable. The O - C curve suggested that the period of GSC 0763-0572 is undergoing a continuous increase at a rate of dP/dt = +5.81(33) x 10(-7) d yr(-1). Photometric solutions were derived by using the Wilson-Devinney code. We confirmed that this system is A-subtype overcontact binary with a degree of contact factor of f = 31.0% (+/- 1.5%), a mass ratio of q = 0.2330, and a temperature difference of Delta T = 31 K. The long-term increase of the orbital period can be explained by mass transfer from the less-massive component to the more-massive one. It's inferred that GSC 0763-0572 may presently be in an expanding state of thermal relaxation oscillation, and may finally evolve into a rapid-rotating single star.