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In this work, the analysis of the photoelectric light curve (LC) in the broad‐band filter (400–700 nm) for the UU And system was carried out using the PHOEBE program (vers. 0.31a). The absolute dimensions of the system are determined and its evolution is discussed. Moreover, the period changes of the system are studied using updated O – C data, which shows a cyclic change with a period of Pmod = 18 yr. This was attributed to a magnetic activity cycle operating in this system. In addition to the cyclic change, a long‐term secular variation due to mass transfer from the secondary to the primary component with a rate of 6.17×10–9 M⊙ yr–1 was also detected. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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This paper presents the first comprehensive study of the EP And system, a contact binary. In this work the solution of the standard V light curve was obtained using the PHOEBE program (version 0.3c). Absolute parameters of the stellar components were then determined, enabling us to discuss the structure and evolutionary status of the close binary EP And. The times of minima data ('OÀC curve') were analyzed. It was found that a third body with a period of 41.20 yr and mass 0.15 M } is orbiting around the system. Also a modulating period of an 11.72-yr cycle along with a relative period increase of DP P ¼ 1:79 Â 10 À7 were obtained, which were attributed to the magnetic activity cycle and mass transfer with rate Dm m ¼ 9:98 Â 10 À8 yr À1 between the components, respectively.

New UBV photometry of Algol type binary star U Sge obtained during 1993 are presented, analyzed, and discussed. Wilson-Devinney code was employed to analyze the light curves. Absolute dimensions of the system were obtained, and positions of both components on H-R diagram were specified. Finally through color curve analysis absolute visual magnitudes were determined.