Scientists witnessed a short blast they dubbed “the Cow” in June 2018 and have now published the results of their study of it. The mysterious explosion in space could turn out to be the birth of a black hole from a collapsed neutron star, according to new research.
Scientists observed the mysterious explosion in space through its x-ray and ultraviolet emissions, believing it was caused by a newborn black hole “eating” a white dwarf star, according to Raffaella Margutti, assistant professor of physics and astronomy at Northwestern University. White dwarf stars are the leftovers of small stars like our sun when their life comes to an end.
“But further observations of other wavelengths across the spectrum led to our interpretation that ‘The Cow’ is actually the formation of an accreting black hole or neutron star,” Margutti explained in a statement.. “We know from theory that black holes and neutron stars form when a star dies, but we’ve never seen them right after they are born. Never.”
Astronomically speaking, the Cow event which hinted at the birth of a black hole was relatively close at 200 million light years from Earth, somewhere in the Hercules constellation. Scientists were successfully able to detect the AT2018cow event using the Asteroid Terrestrial-Impact Last Alert System (ATLAS) in Hawaii. Since the event was very bright, scientists detected it quickly, although it lasted for only a brief time, fading away only after a few weeks.
“We knew right away that this source went from inactive to peak luminosity within just a few days,” co-author Ryan Chornock of Ohio University said. “That was enough to get everybody excited, because it was so unusual and, by astronomical standards, it was very close by.”
Scientists were able to train telescopes around the world to look after the mysterious light sources. Margutti’s team was studying the mysterious explosion in space using x-ray wavelengths from NASA’s Nuclear Spectroscopic Telescope Array (NuSTAR) and the European Space Agency’s International Gamma-Ray Astrophysics Laboratory (INTEGRAL) and XMM Newton spacecraft.
Using telescopes at the Keck Observatory in Hawaii, the team learned about the chemical cover of the Cow. Their study revealed the presence of hydrogen and helium, which are associated with black holes and neutron stars. It’s well-known that black hole creation involves either a collision of two galaxies or the collapse of a neutron star on its own mass, with the latter being observed less frequently.
“It took a while for us to realize what we were looking at — I would say months,” co-author Brian Metzger of Columbia University said. “We tried several possibilities and were forced to go back to the drawing board multiple times. We were finally able to interpret the results, thanks to the hard work of our incredibly dedicated team.”
The researchers published the results of their study on the birth of the black hole in The Astrophysical Journal.