Event Date and Time
Veronique Petit, University of Delaware
Hot O-, B-, and A-type stars lack the vigorous subsurface convection thought to drive the dynamos that produce the magnetic activity of the Sun and other cool stars. It therefore came as a surprise when strong, organized magnetic fields were discovered in a subset of intermediate mass “ApBp” stars, with field strengths ranging from 100 - 10,000 gauss. In the past decade, large survey programs such as the Magnetism in Massive Stars (MiMeS) Project have exploited the new generation of optical spectropolarimeters to extend the characterization of stellar magnetism to a growing subset of massive O and early-B stars. These magnetic massive stars host strong, stable, and nearly dipolar surface fields similar to magnetic ApBp stars. Observational and theoretical work has now established that these fields are surviving remnants from an earlier event, or an earlier evolutionary phase. However, many important questions remain regarding the exact formation and/or evolution scenarios capable of producing similar magnetic characteristics across the broad mass range covered by OBA stars. What is also not known is the consequence of these so-called “fossil” fields on the late stages of stellar evolution as well as their impact on the core-collapse mechanism, and the formation of exotic compact objects such as magnetars and gravitational wave progenitors.