Rotational measurement and study of RS CVn binaries. II

Abstract

For 37 components belonging to 31 RS CVn binary systems, we measured the rotation using Reticon data on the 2.1 McDonald Reflector. Combining our previous data for 38 components, we made a statistical analysis on the question of synchronous rotation. Our results show that, while the great majority show synchronous rotation, exceptions are found in all period groups, contradicting the generally held view that all short period and normal period RS CVn stars have synchronous rotation and all long period ones do not.