Algol-türü Örten Çift UU And'ın O-C Analizi

Abstract

Using all available minimum times of Algol-type eclipsing binary UU And, Observed(O) - Calculated (C) based orbital period analysis of UU And is presented in this study. O-C diagram of UU And is represented by cyclic variation superimposed on an upward parabolic variation. The upward parabolic variation was modelled by assuming non-conservative mass transfer from the less massive to the more massive component to explain the secular period increase of the system. The rate of fractional mass transfer (β) was calculated to be 0.947. Cyclic O-C variation at period of 14 years was detected in the diagram. Light travel time effect (LTTE) caused by additional body in the system was assumed in order to explain the cyclic O-C variation. Using the mass function obtained from O-C analysis, the possible mass of the third component was found to be in the order of solar mass. Such a massive additional body show itself distinctly in the light curve of UU And. On the contrary, no light contribution from an additional body has been detected in the literature so far. Therefore, we conclude that precise high resolution spectroscopic observations are required in order to clarify the existence of a third body and/or magnetic cycle, which may also give rise to cyclic O-C variation in the binary star system.