Activity cycles in RS CVn-type stars

Abstract

ABSTRACT We compile a list of 120 RS CVn-type stars from the bibliography in Southern hemisphere, to search for rotation periods and activity cycles, covering a large range of luminosities and effective temperatures for late stars. For each system of the list, we use photometric data from the All Sky Automated Survey (ASAS), and complement it with our own photometry, obtained with the Optical Robotic Observatory (ORO). We analyse these data with the Generalized Lomb–Scargle (GLS) periodogram to determine the rotation period and possible activity cycles for each system. We found rotation periods for 102 systems and activity cycles for 91 systems. From the statistical analysis of the results, we found that giant stars behave differently than subgiants and main-sequence stars, and that there is a good correlation between rotation periods and luminosities.