Activity cycles in RS CVn type stars

TL;DR

This study analyzes activity cycles in 121 RS CVn stars using photometric data to identify rotation periods and activity cycles, revealing differences in behavior among stellar types and a correlation between rotation and luminosity.

Contribution

It provides the first comprehensive analysis of activity cycles across a large sample of RS CVn stars, combining survey and own observations with periodogram analysis.

Findings

Rotation periods identified for 102 stars.

Activity cycles detected in 91 stars.

Giant stars show different activity behavior than subgiants and main-sequence stars.

Abstract

We compile a list of 121 RS CVn type stars from the bibliography in southern hemisphere, to search for activity cycles, covering a large range of luminosities and rotation periods. For each system of the list, we obtain photometric data from the All Sky Automated Survey (ASAS), and we complement it with our own photometry, obtained with the Optical Robotic Observatory (ORO). We analyze this data with the Generalized Lomb-Scargle 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.