A study of the long term photometric variation of the RS CVn star V711 Tau

Abstract

With a view to investigate the long term photometric behaviour of one of the most active double lined spectroscopic RS CVn type binary V711 Tau (K1 IV + G5 V) we examine its light curve for the last eighteen years (1977 - 1995). The light curve of this binary shows remarkable changes in terms of shape, amplitude as well as the phase of the minimum light. We parameterize these light curves in the framework of the starspot model to derive spot parameters (size, spot temperature, location etc.) to look for any systematic secular variation in them. The light curves could reliably be synthesized with a minimum of three spots with one always at the pole. The study however does not indicate any systematic secular variation in spot parameters.