Sun like activity from active stars and its implications

Abstract

The heliographic equator is investigated using the source surface model of the heliomagnetic field. Considering only the dipole and guadrupole terms in the sperical harmonic expansion of the potential solar field, the heliosheric current sheet on the source surface is identified as the thin neutral sheet where the radial component of the field goes to zero. It is shown that a system (i) with eccentric dipole or (ii) with a tilted dipole equatorial quadruple can assign north-south asymmetry to the heliospheric current sheet. The observed north-south asymmetry in the heliospheric current sheet can thus be understood in the terms of the relative strengths and phase angles of the various multipoles present in the heliomagnetic field.