New Type of Supernova Discovered

Astronomers have discovered Type Iax supernova- a new kind of supernova  that's fainter and less energetic than previously known supernovas.

There are basically two types of supernovas; the core-collapse supernova, which is the explosion of a massive star that's about 10 to 1,000 times bigger than our sun and the Type Ia supernova, which is the complete disruption of a tiny white dwarf.

"A Type Iax supernova is essentially a mini supernova. It's the runt of the supernova litter," said Ryan Foley, Clay Fellow at the Harvard-Smithsonian Center for Astrophysics (CfA) and lead author of the study.

For the study, researchers identified 25 examples of new type of supernovas. They found that none of the supernovas came from old starts. The observational data showed that this type of supernova comes from a binary star system where a white dwarf has a companion star that has lost its outer hydrogen ring. The white dwarf then collects the helium from the normal star.

Researchers aren't sure what leads to the formation of a Type lax.One reason might be that the helium layer may first explode, sending a kind of shockwave in the white dwarf. Another theory is that it may be the white dwarf that explodes first due to the presence of the helium shell.

However, unlike the Type la supernova, the white dwarf in the Type lax survives, researchers said.

"Type Iax supernovas aren't rare, they're just faint," said Foley in a news release. "For more than a thousand years, humans have been observing supernovas. This whole time, this new class has been hiding in the shadows."

The study is published in The Astrophysical Journal.