Stars that go Boom
Smithsonian Astrophysical Observatory
Type Ia Supernovae are powerful explosions that can be as bright as an entire galaxy. Astronomers use these supernovae as standard candles to constrain the cosmological models and study the distribution of dark matter and dark energy in the Universe. However, to date, we do not know what creates these explosions. Mergers of binary white dwarf stars are one of the proposed channels for the formation of Type Ia supernovae. Short period binary white dwarfs may merge within a Hubble time due to gravitational wave radiation. We have begun a targeted survey to find merging white dwarf systems, and our first results have tripled the number of known merging white dwarf systems. Our sample includes systems with orbital periods as short as 40 minutes and with merger times less than 40 Myr. I will discuss the characteristics of this merger sample and potential links to Type Ia and underluminous supernovae.
Date: Friday, 25 February 2011 Time: 14:00 Where: Université de Montréal Pavillon Roger-Gaudry, Local Z-300 Contact: Pierre Bergeron