IUE observations of certain short period RS CVn-like stars

Abstract

Nine low and one high resolution IUE (LWR) spectrograms for the short period subgroup RS CVn-like stars have been studied, particularly in connection with the MgII 2800 Å feature. Clear emission contributions can be easily seen for some of these stars, while all nine of them appear to have the feature filled by emission to some extent. If surface flux in emission is considered as a measure of 'activity' (and not just equivalent width) the short period subgroup is as active as the main group. The activity is not as obvious because of the generally higher photospheric temperatures. Correlations of such activity with angular velocity and the scale of irregular photometric distortions ('starspots') are present, though the sample size is low.