New class of 'mini supernovae' discovered

[Craig]

http://physicsworld.com/cws/article/news/2013/apr/02/new-class-of-mini-supernovae-discovered

A new type of supernova has been defined by researchers from the US. Designated type Iax, this new class is seen to be less energetic and fainter than previously defined and similar type Ia events – and may even leave behind part of its originating star.

Previously, only two classes of supernovae were recognized – core-collapse events, the explosion of stars 10–100 times as massive as our Sun, and type Ia supernovae, which involve the complete destruction of a white dwarf. Now, a team led by Ryan Foley at the Harvard-Smithsonian Center for Astrophysics has identified 25 members of the new type Iax class based on optical spectroscopic and photometric studies. Its work has shown these stars to be less energetic and with a lower absolute magnitude than would be expected with their type Ia cousin. The team believes that the supernovae of this new class originate from a binary star system comprised of a white dwarf that gathers helium from a companion star, which has lost its outer hydrogen.