Failed explosions explain most peculiar supernovae

Supercomputer simulations have revealed that a type of oddly dim, exploding star is probably a class of duds—one that could nonetheless throw new light on the mysterious nature of dark energy. Most of the thousands of exploding stars classified as type Ia supernovae look similar, which is why astrophysicists use them as accurate cosmic distance indicators. They have shown that the expansion of the universe is accelerating under the influence of an unknown force now called dark energy. Yet approximately 20 type Ia supernovae look peculiar. "They're all a little bit odd," said George Jordan, a research scientist at the University of Chicago's Flash Center for Computational Science. Comparing odd type Ia supernovae to normal ones may permit astrophysicists to more precisely define the nature of dark energy, he noted. Jordan and three colleagues, including his chief collaborator on the project, Hagai Perets , assistant professor of physics at Technion - Israel Institute of Technology , have found that the peculiar type Ia supernovae are probably white dwarf stars that failed to detonate.