RS CVn STARS: Photospheric Phenomena and Rotation

Quiescent and Flaring Structure in Rs Cvn

AM CVn stars

I review our observational and theoretical knowledge of AM CVn stars, focusing on recent developments. These include newly discovered systems, the possibility that two recently discovered extremely short period objects are AM CVn stars and an update on X-ray, UV an optical studies. Theoretical advances include the study of the details of both the donor and accretor, and the physics of the heliu...

Letter to the Editor Permanent active longitudes and activity cycles on RS CVn stars

A new analysis of the published long-term photometric observations has revealed permanent active-longitude structures in four RS CVn stars: EI Eri, II Peg, σ Gem, and HR 7275. Two active longitudes separated by half of the period are found to dominate on the surface during all available seasons. The positions of the longitudes on three stars (EI Eri, II Peg, HR 7275) are migrating in the orbita...

A NON-EMPIRICAL ROTATION-ACTIVITY RELATION FOR RS CVn BINARIES USING RADIO LUMINOSITIES

An analysis of a comprehensive survey of radio luminosities for RS CVn binary systems is given. A comparison is made between the rotation-activity correlations found using the usual semi-empirical Rossby number and a Rossby number deduced from detailed convection zone models. The use of a non-empirically derived Rossby number does not signiicantly improve the rotation-activity correlation. Alth...

VLA multifrequency observations of RS CVn binaries

We present multiepoch Very Large Array (VLA) observations at 1.4 GHz, 4.9 GHz, 8.5 GHz and 14.9 GHz for a sample of eight RS CVn binary systems. Circular polarization measurements of these systems are also reported. Most of the fluxes observed are consistent with incoherent emission from mildly relativistic electrons. Several systems show an increase of the degree of circular polarization with ...