2021-03-30, 15:00: Dr. Stanley Owocki (University of Delaware)
Dr. Stanley Owocki
University of Delaware, USA
Magnetospheres of Magnetic Massive Stars
Abstract: Massive, luminous, hot stars lack the hydrogen recombination convection zone that induces the magnetic dynamo cycle of cooler, solar-type stars. Nonetheless, modern spectropolarimetry has revealed that about 10% of O, B and A-type stars harbor large-scale, organized (often predominantly dipolar) magnetic fields ranging in dipolar strength from a few hundred to tens of thousand Gauss. This talk will discuss the role of such fields in channeling and trapping the radiatively driven winds of such massive stars. A particular focus will be on the interplay of rotation and magnetic fields. This includes: (1) the rotational spindown from angular momentum loss from open field regions; (2) the centrifugal support of material in closed loops; and (3) the role of centrifugal breakout in balancing the mass accumulation from the magnetically trapped stellar wind. I will conclude with brief remarks on potential overlap with processes in planetary magnetospheres.