Scientists have found what appears to be a black hole formed during a supernova observed 30 years ago.
"If our interpretation is correct, this is the nearest example where the birth of a black hole has been observed," said Daniel Patnaude, the astrophysicist who led the team that found the black hole, in a statement Monday.
Patnaude, a scientist at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., and his team are publishing their results in the New Astronomy journal, said a NASA news release.
The new black hole is believed to be a remnant of SN 1979C, a supernova discovered by an amateur astronomer in 1979. A supernova is the bright explosion of a massive star at the end of its lifetime — in this case, the star was about 20 times more massive than the sun and located in a galaxy called M100, about 50 million light years from Earth.
A star's collapse under the weight of its own gravity after the explosion may generate a black hole. X-rays are emitted by gas falling into the black hole.
The new apparent black hole was discovered from the X-rays it emitted between 1995 and 2007. They were detected using NASA's Chandra X-ray Observatory, NASA's Swift satellite, the European Space Agency's XMM-Newton observatory and the German ROSAT observatory.
Abraham Loeb, a researcher at the Harvard-Smithsonian Center who co-authored the paper, said detecting this type of black hole birth is difficult because it requires decades of X-ray observations.
A supernova does not always collapse into a black hole — sometimes the collapse is halted before a black hole is formed, generating a very dense star called a neutron star.
Although the evidence suggests the remnant of SN 1979C is a black hole, it may in fact be special kind of neutron star called a pulsar wind nebula. That would make it the youngest known neutron star, NASA said.
Most known young black holes are a special kind that emit radiation called gamma ray bursts. However, astrophysicists predict that most black holes in the universe, such as the newly discovered object, do not produce gamma ray bursts.