Supernova reserve fuel tank clue to big parents »

Some supernovae have a reserve tank of radioactive fuel that cuts in and powers their explosions for three times longer than astronomers had previously thought. A team of astronomers jointly led by Dr Ivo Seitenzahl from ANU  Research School of Astronomy and Astrophysics detected the faint afterglow of a supernova, and found it was powered by radioactive cobalt-57. The discovery gives important new clues about the causes of Type Ia supernovae, which astronomers use to measure vast distances across the Universe. Dr Seitenzahl said the discovery of cobalt-57 fingerprints in a Type Ia supernova gave insights into the star that exploded and suggested it was at the top of its weight range. "This explosion suggested that it was a star stealing matter from an orbiting partner until it got so massive that its core of carbon ignited and set off the explosion," said Dr Seitenzahl. "It's exciting to work this out because there are conflicting theories about what causes Type Ia supernovae. "It's curious to me that we still don't know exactly what these things are, even though they are so important for cosmology." Type Ia supernovae are explosions that can be seen even in far-away galaxies and help astronomers study the large-scale structure of the Universe.