16 November 2006

Speaker: Gary Schmidt (University of Arizona)

Title: Funnels, Siphons, and Winds, "Oh, My!" The Weird and Wonderful World of Magnetic Accretion

Abstract: Accretion lies at the heart of most of the cataclysmic eruptions in the Universe: from novae, to some supernovae and gamma-ray bursts, to the beamed jets of active galactic nuclei. While magnetic fields are probably present in most of these situations, rarely does magnetism play a dominant role in the accretion process. When it does, we witness rare and remarkable dynamical and emission processes that otherwise may be found only in textbooks. Recent studies of magnetic cataclysmic variables - those containing a strongly magnetic white dwarf - have uncovered yet another regime of magnetic accretion, where a shock does not form, and the atmosphere of the accreting star stays relatively cool. The binary systems accreting by this "bombardment" mechanism have a great deal to tell us about not only physics, but also the formation and evolution of close binaries, and they are providing new basic information on the most common stars in the Universe. These and other aspects of the exotic world of magnetic accretion will be reviewed in in this talk.