The Variability of Magnetic Stars

Abstract

Magnetic fields are found in a wide variety of stars, including some upper main sequence stars, many lower main sequence stars, some cool giants, and a small fraction of white dwarfs. The fields of A and B stars, and those of the magnetic white dwarfs, seem to be structurally quite simple and to have intrinsic surface structures that do not change with time. Such magnetic fields may be mapped by observing how they appear to change as the underlying star rotates. The fields of cool stars seem to be more complex, like that of the sun, and to vary intrinsically on observable time scales. In such a star, observed variations may be used to map the instantaneous structure of the field and its associated non-thermal activity, and also to study such phenomena as differential rotation of active regions and cycles of activity.KeywordsMain SequenceZeeman SplittingZeeman EffectMain Sequence StarCool StarThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.