Matthew Shultz, University of Delaware
Magnetic fields are found in about 10% of stars with radiative envelopes. They are typically strong, simple, stable, and are not maintained by contemporaneous dynamos, for which reasons they are described as 'fossil' fields, i.e. fields left over from an earlier period in a star's life. Amongst stars earlier than about B5, magnetic confinement of their powerful winds leads to the formation of magnetospheres which can be detected across the electromagnetic spectrum, and which in turn are expected to lead to rapid angular momentum loss.