To Re-analyze orbital period change of the RsCVn type binary star RT andromedae

ABSTRACT The (0-C) diagram formed by all available published times of minima of RT Andromedae were intensively analyzed to deduce the general form of period variation for RT And. It is established that the orbital period change of the system has a quasi-sinusoidal form superposed on a downward parabola. Such variations of the orbital period have been examined in terms of three plausible mechanisms, namely (i) mass loss or mass transfer, (ii) a light-time effect due to an unseen third star in the system, and (iii) a orbital period modulation due to magnetic activity cycle of a component star. Only the future data will add information on the nature of the secular (O-C) variation. Secular light variation of the system was also studied and was found no correlation with the orbital period variation. Key words: stars: binaries: close - stars: individual: RT Andromedae - orbital period variation - light changes.