Stellar activity in the RS CVn binary star UX Arietis

Abstract

Using our data along with the photometric data available from the literature, we have made extensive analysis of the light variations of UX Ari. The parametric study of the photometric data for the last 22 years in the frame work of a starspot model indicates that the spot activity of UX Ari varies periodically with time-scale of nearly 18 years. The distribution of the reliable parameter, the spot longitude, indicates that spots have a tendency to concentrate within two longitudinal belts. The continuous observations of UX Ari during the period from November 1995 to February 1997 reveal appreciable variation in amplitude as well as in the shape of light curves over a time scale as short as a couple of rotation period.