Photometric study of the RS CVn binary II Pegasi

Abstract

An analysis of available data and of B and V photometry obtained at Kavalur on 39 nights during the 1980-81, 1981-82, and 1984-85 observing seasons of II Peg shows no two light curves to agree in shape, amplitude, phases of light maxima and minima, mean light level, or brightness at the light maxima and minima. Phases of the light minima from the 1979.83-1980.97 interval are shown to lie on two distinct lines with different slopes, implying the simultaneous existence of two centers of activity located at different latitudes and longitudes on a differentially rotating star. No correlation between the color (B-V) and the visual magnitude is noted, though a large scatter with a total range of about 0.1 mag is found