M University of Minnesota
  Search Physics:
  
Now Accepting Graduate Applications   
CONTACT INFORMATION
School of Physics & Astronomy
116 Church Street S.E.
Minneapolis, MN, 55455
Phone: 612-624-7375
Fax: 612-624-4578
Contact | Directory

Physics and Astronomy Calendar

Friday, October 26th 2007
3:00 pm:
Astrophysics Colloquium in 210 Physics
Speaker: Dr. Dean Townsley, University of Chicago
Subject: Explosions in Mass Transferring White Dwarf Stellar Binaries
Refreshments served following the talk in the Astronomy Reading Room, 358 Physics

White Dwarf (WD) stars are the most common stellar remnant, being produced by all stars below about 8 times the mass of our sun. Put in a close binary, a WD can gain mass from a companion and undergo a variety of bright, dynamic outburst phenomenon driven by both accretion and thermonuclear explosion. I will discuss how we study the WDs in these systems, during both outburst and quiescence, and what we are learning about their population as a whole and how these binaries form and evolve. I will highlight the ignition of the brightest outbursts they make: Classical Novae -- due to thermonuclear runaway in hydrogen-rich material on the WD surface -- and Supernovae -- due to carbon-burning thermonuclear runaway in the deep interior. Particular attention will be paid to how the features of the evolution of the binary might determine aspects of the explosions. These systems are thought to produce the Supernovae of Type Ia, which have remarkably regular characteristics and are therefore of great interest as standard candles for cosmology. Interesting puzzles remain in our theoretical understanding of these systems and their remarkable outbursts.

The weekly calendar is also available via subscription to the physics-announce mailing list.