Type la Supernovase: Nature's Grandest Thermonuclear Explosions

Prof. Stanley Woosley, University of California, Santa Cruz

Type Ia supernovae are the biggest thermonuclear explosions in the modern universe. They occur when a white dwarf star accretes a critical mass from a companion and ignites carbon fusion in its center. The ensuing burning produces roughly 0.7 solar masses of radioactive nuclei that cause the supernova to glow as brightly as a galaxy for about two weeks. There are four problems which impede a first principles understanding of Type Ia supernovae that goes beyond these qualitative assertions: a) What is the nature of the stellar system where this runaway occurs? b) Where and how often does the fusion flame ignite? c) Once ignited, how does the flame move in response to its own Rayleigh-Tayor instability and the turbulence it makes? Does it detonate? and d) Why does the resulting light curve exhibit the obserevd witdth-luminosity relation so valued by cosmologists (and what does this say about the models). I will ignore question a) but discuss the current attempts to understand b), c) and d).

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