NASA’s Hubble Space Telescope has captured the first image of a star that escaped from a supernova explosion. Called SN 2001ig, the star explosion took place 40 million light-years away from Earth in the NGC 7424 galaxy, which is located in the southern constellation Grus, the Crane.
Astronomers were able to identify the exact location of the supernova using the European Southern Observatory’s Very Large Telescope (VLT) and the Gemini South Observatory in Chile. Notably, this is the first time that a surviving companion has been photographed.
Stuart Ryder, the lead author of the study from the Australian Astronomical Observatory (AAO) in Sydney, claimed that most of the massive stars are in binary pairs. He added that many of such binary pairs interact and transfer gas from one star to the other when their orbits bring them close together.
According to the researchers, SN 2001ig siphoned off almost all of the hydrogen from the doomed star’s stellar envelope, so, they have categorized it as a Type IIb stripped-envelope supernova. Such supernova explosions are considered to be fairly unusual as most of the hydrogen is gone prior to the explosion. This kind of exploding star was first identified back in 1987 by Alex Filippenko of the University of California, Berkeley.
Notably, scientists have not yet been able to find out how such stars lose their outer envelopes. Although prior studies have suggested that such type of supernova originated from single stars with very fast winds that pushed off the outer envelopes, astronomers have not been able to find evidence of primary stars responsible for such explosions. Primary stars are space bodies that do not have binary companions.
“That was especially bizarre, because astronomers expected that they would be the most massive and the brightest progenitor stars,” Ori Fox, a researcher from the Space Telescope Science Institute in Baltimore, said in the statement.
Fox added that the number of stripped-envelope supernovas is actually more than predicted. As per the theory, published in The Astrophysical Journal, up to half of Type IIb supernovae may be binary stars, while the other half lose their outer envelopes via stellar winds.