Oddball stellar explosion doesn’t match known outbursts
Just in time for July 4, astronomers say they have found a new type of stellar firecracker.
Stars that die an explosive death generally fall into two categories: young, massive stars that collapse under their own weight and hurl their outer layers into space, and older, sunlike stars that undergo a thermonuclear explosion. But the stellar explosion recorded in January 2005 and known as SN 2005E doesn’t fit either class, according to a new analysis reported online June 11 at arXiv.org.
The explosion ejected only a small amount of material — the equivalent of 0.3 solar masses — and erupted in the halo of an isolated galaxy, a region devoid of any star formation. These findings suggest that the explosion, or supernova, did not arise from the collapse of a massive star, report study coauthors Hagai-Binyamin Perets and Avishay Gal-Yam of the Weizmann Institute of Science in Rehovot, Israel, and their colleagu