NASA recently announced that it detected a star that escaped from a supernova explosion. Called SN 2001ig, this took place in a galaxy of the constellation Grus.
Located about 40 million light-years from Earth, the star escaped from the explosion of its binary companion. Most large stars are binary, according to Stuart Ryder of the Australian Astronomical Observatory. A “survivor” like this has never before been detected.
The Lone Survivor of the Supernova Explosion
According to research from NASA, the two stars of this binary system orbited each other over the course of about a year. However, in the process, the surviving star was siphoning off the hydrogen from its neighbor’s stellar envelope, which helped bring about the supernova explosion.
That makes SN 2001ig a Type IIb supernova, or a stripped-envelope supernova. Until now, scientists were not sure how such stars lost their outer envelopes. The presumed culprit were and still are powerful stellar winds.
“That was especially bizarre because astronomers expected that they would be the most massive and the brightest progenitor stars,” said Space Telescope Science Institute researcher Ori Fox.
He also noted that the number of Type IIb supernovae is higher than predicted. According to a new theory, published in the March 28 issue of The Astrophysical Journal, up to half of Type IIb supernovae may be binary stars. Also, the remaining ones might lose their envelopes due to the aforementioned stellar winds.
Both the European Southern Observatory and the Gemini South Observatory in Chile spotted SN 2001ig and its escapee.