Observations of stellar magnetism and associated phenomena

University of Western Ontario, London, Ontario, Canada, and Armagh Observatory, Armagh, UK

Abstract

This paper first surveys how stellar magnetic fields are measured, and especially the impact of the most recent spectropolarimeters on our measurement capabilities. The two main types of stellar magnetism, dynamo and fossil fields, are discussed in a general way. This is followed by a broad survey of the current level of knowledge of magnetic fields in various classes of stars, from the pre-main sequence through main sequence stars, giants, and white dwarfs. Some of the hotter magnetic stars show clear abundance anomalies relative to the solar abundance ratios. The connection between magnetism and the atomic diffusion believed to be responsible for these anomalies is discussed, especially in the context of some new results from cluster A and B magnetic stars.