Colloquium
Illuminating the Glowing Magnetospheres of Massive,
Luminous Stars
Dr. Richard Townsend
Bartol Research Institute
University of Delware
Tuesday, February
12, 2008,
1:40 p.m., SCIC 126
Massive, luminous stars are not expected to harbor
magnetic fields, owing to their lack of envelope convection zones and
associated field-generating dynamos. Puzzlingly, however, it has been known
since the 1970s that a small yet growing subset of massive stars possess
strong, global-scale fields. These fields channel and confine the stars'
supersonic, radiatively driven winds, leading to
the formation of glowing, co-rotating magnetospheres that can be observed
across the electromagnetic spectrum, from X-rays through to radio.
My interest in massive-star magnetospheres stems from
the challenge of understanding the rich variety of phenomena they manifest,
at a detailed, quantitative level. In my presentation, I aim to illuminate
the basic physical processes responsible for the existence of these
magnetospheres. Then, with the aid of extensive animations, I will
introduce the new 'Rigidly Rotating Magnetosphere' and 'Rigid Field
Hydrodynamics' models that I have developed for understanding magnetospheric signatures at optical, UV and X-ray
wavelengths.
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