High-Energy Phenomena in Be Stars (Review Paper)

Abstract

It was discovered in the early years of the Copernicus satellite operations that the stellar winds in early-type stars are often characterized by degrees of ionization inconsistent with the spectral types of the stars. The most notable early example was the discovery of strong OVI lines in the form of P Cygni profiles in stars too cool to have this ion in their photospheres, such as τ SCO (BOV; Rogerson and Lamers 1975). Systematic studies showed that excess ionization is a general property of the winds in OB stars (e.g. Lamers and Snow 1978).