A Study of the Coronal Plasma in RS CVn binary systems

Abstract

XMM-Newton has been performing comprehensive studies of X-ray bright RS CVn binaries in its Calibration and Guaranteed Time programs. We present results from ongoing investigations in the context of a systematic study of coronal emission from RS CVns. We concentrate in this paper on coronal abundances and investigate the abundance pattern in RS CVn binaries as a function of activity and average temperature. A transition from an Inverse First Ionization Potential (FIP) effect towards an absence of a clear trend is found in intermediately active RS CVn systems. This scheme corresponds well into the long-term evolution from an IFIP to a FIP effect found in solar analogs. We further study variations in the elemental abundances during a large flare.Comment: to appear in The Twelfth Cool Stars, Stellar Systems and the Sun, eds. A. Brown, T.R. Ayres, G.M. Harper, (Boulder: Univ. of Colorado), in pres