Dynamo models and the flip-flop phenomenon in late-type stars

Abstract

The 'flip-flop' phenomenon has now been found to occur on several late-type stars: active longitudes, associated with dark regions of the surface, are seen to jump by 180°. A simple non-linear non-axisymmetric mean field dynamo model is described, in which for the first time magnetic behaviour is found that is akin to the observed flip-flop.