Nonaxisymmetric cool spot distributions and dynamo action in close binaries

摘要: We investigate the nonaxisymmetric magnetic field distribution in components of close binary systems, gen- erated by a stellar dynamo with the-coecient, proportional to mean helicity convective motions envelope. The nonaxisymmetry is assumed be connected interaction companion, i.e. reflection eect and tidal interaction. degree asymmetry estimated from known parameters ER Vulpeculae, an active RS CVn-type star. demonstrate that synchronization rotation orbital motion Vulpeculae due sucient allow structures survive presence smoothing dierential rotation. driven are usually steady reference frame the-spot. However, we found resonant excitation oscillatory, strongly nonaxisym- metric, configuration, joint action the-eect obtained predominantly manifested on surface form spots radial field. Their size similar cool observed surfaces both their displacements the-spots comparable hot eect. Possible relevant observations discussed.