Standard-Candle Supernovae are Still Standard, but Why?

Lawrence Berkeley National Laboratory: Until recently, scientists thought they knew why Type Ia supernovae - the best cosmological "standard candles" - are all so much alike. But their favorite scenario was wrong. White dwarfs don't all reach the Chandrasekhar limit, 1.4 times the mass of our sun, before they detonate in a massive thermonuclear explosion. Most Type Ia progenitors are less massive, and a few are even more massive. New work by the Berkeley Lab-based Nearby Supernova Factory can id...