Narrator: This is Science Today. Astronomers working at the Lawrence Berkeley National Laboratory's Nearby Supernova Facility discovered 34 supernovae last year, the best performance ever for a 'rookie' supernova search. Greg Aldering, a principle researcher, says that by studying the brightness of stars as they die, we can understand the expansion history of the universe.Aldering: And the thing that is interesting about these particular kind of supernovae, they basically convert similar amounts of mass into energy and therefore, in the end, they end up having similar brightnesses.
Narrator: By finding an average brightness, Aldering and his team can estimate the distance of supernovae within 5% accuracy, which is amazing by astronomical standards.
Aldering: What we do is exploit that to look at supernovae that are halfway across the universe. And we can measure how much the universe has expanded between the time that that supernova blew up and the time that we see the light.
Narrator: For Science Today, I'm Larissa Branin.