Magnetic Activity in Close Binaries

Abstract

Solar-like magnetic activity indicators such as photospheric spots, chromo spheric emission, coronal X-ray and radio emission, and flare activity are commonplace in many cool stars with convective envelopes (spectral types of about F5 and later). Generally, the strength of stellar activity increases with more rapid rotation and later spectral types which corresponds to the increasing depth of the star's convective envelope. The origin of this solar-like activity is believed to be a magnetic dynamo in which magnetic fields are generated in the differentially rotating convective zones of the Sun and solar-type stars. Unfortunately, although the magnetic dynamo model is generally accepted to explain both solar and stellar activity, it is only poorly understood and inadequately tested to date (see Parker 1981; 1986).