HMC Physics Colloquium

Tuesdays at 16:30 in Shanahan Center for Teaching and Learning, Room B460

E. Sterl Phinney


Mergers and Liquidations Among White Dwarf and Neutron Star Binaries

Nov. 8, 2011

This year’s Nobel prize in physics was given for using Type Ia supernovae as standard candles to discover that dark energy now dominates the dynamics of the universe. Disconcertingly, recent research has uncovered problems with both of the two popular models for Type Ia supernovae. One is in trouble with observational data, and the other with careful theoretical calculations, which point to quite a different outcome. Since Type Ia supernovae are nevertheless observed, a rather embarrassing situation is developing — we have no idea what Type Ia supernovae actually are. The new outcomes, however, may solve other long-standing problems. The second part of the talk will discuss recent observational and theoretical work on pulsars with very low mass binary companions (one possible outcome of the Type Ia supernova failures). The ultra-high energy particles from these “Black Widow” pulsars create showers in the atmospheres of their companions which dramatically heat and even evaporate them.