Karen S. Bjorkman
(Circumstellar Disks, Polarimetry, and Stellar Winds)

Distinguished University Professor of Astronomy, and Department Chair
Ph.D. Astrophysics, 1989 - University of Colorado

Personal Homepage
My research interests are in the material around stars (circumstellar matter) and in the winds from hot stars. Evidence of circumstellar disks is seen in many types of stars, from the earliest young stars to older planetary nebulae, and the presence of disk-like geometries seems to be ubiquitous in the stellar zoo. Studying such systems can help to shed light on the ways that stars are formed, and possibly even on the development of protoplanetary systems around other stars. Some questions we ask about winds, disks and circumstellar material include: What causes disks to form around massive stars? Are there interactions between stellar winds and circumstellar disks, and if so what are their consequences? What are the disks like? (are they thick or thin? hot or cool? high or low density?) How do disks affect the evolution of the star and the interstellar medium around it? Are there similarities between the disks observed in pre-main-sequence (young) stars, which may be the precursors to planetary systems, and those) observed in main-sequence (older) stars?  In studying these questions, I use several observational techniques (spectroscopy, spectropolarimetry, and imaging) at multiple wavelengths (optical, ultraviolet, and infrared). Combining different types of observations can help develop a consistent picture of the nature of circumstellar envelopes and disks. These data are also used for comparison with models, which allows us to distinguish between different ideas of how disks form and what their physical characteristics are.

List of Publications:
(Full bibliography available here via NASA ADS)

E-mail: karen.bjorkman _at_ utoledo.edu


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