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Supernova Twins: Making Standard Candles More Standard Than Ever

Supernova Factory group (SN factory) - Greg Aldering, Kyle Boone, Hannah Fakhouri and Saul Perlmutter.

Type Ia supernovae are bright “standard candles” for measuring cosmic distances. Standard enough to discover dark energy, they’re far from identical. Researchers at the Berkeley Lab-based Nearby Supernova Factory have shown that supernova twins with closely matching spectra double the accuracy of distance measures.

Standard-Candle Supernovae are Still Standard, but Why?

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 identify which theories of the strange circumstances that lead to a Type Ia explosion actually work and which don’t.