Survey gives clues to origin of Type Ia supernovae

The 2011 Nobel Prize in Physics was awarded for groundbreaking use of supernovae to measure the expansion of the universe, which yielded a surprise: it’s accelerating, not slowing down. Nevertheless, astronomers have been unsure what type of explosion produces these bright supernovae. A new study using the Subaru Telescope suggests that Type Ia supernovae come from the merger of two white dwarfs, not one white dwarf grown fat by feeding off its companion.
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