KW Persei -a near-contact system?

An analysis of UBV photoelectric photometry for the eclipsing binary KW Per based on new observational data is presented. The light changes are not only due to eclipses, but also to activity in the system. The U, B and V light curves are analyzed by the Binary Maker 2.0 and Wilson-Devinney codes to derive the geometrical and physical parameters of the system. Since the O'Connell effect is present on the light curves in the three colours, the unperturbed parts of the light curves are considered to represent the quiet stage of the system, in contrast to the active stage which is represented by the perturbed parts of the light curves. The discussion about the evolutionary status of the system indicates that the secondary component of the binary system is an evolved star and the primary is a MS star.