Photometric study of the semidetached eclipsing binary UW Bootis

In this research the wide band (400–700 nm) along with BV light curves (LCs) analysis and spot modeling of the UW Boo system, were carried out using the PHOEBE (v 0.31a) program. Then absolute dimensions of the system were determined. In addition, times of minima data (“O-C curve”) were analyzed. Apart from an almost parabolic variation in the general trend of O-C data, indicative of a secular decrease in the orbital period with rate −0.007 sec/yr, which was attributed to mass and angular momentum loss from the system, a sinusoidal variation with a period of 23±2 yr, modulating the orbital period, was found and attributed either to a third body circling around the system, or to a magnetic activity cycle operating in the system. The evolutionary status of the system was determined, using the results of LCs analysis. This shows that the primary is a typical Main Sequence (MS) star while the secondary is a bit evolved subgiant. It is notable that this is the first comprehensive study of the system.