Don't have a cow, man. With the first observations of the formation of a black hole or neutron star in hand, astronomers will be able to better understand what happens in the moments that a star dies, and a odd new object springs into being.
Officially called AT2018cow, the object has been nicknamed "The Cow", and if it is indeed a neutron star or a black hole - both of which can form when a massive star collapses - it will help scientists understand what exactly takes place when that kind of event occurs. The bright glow was caused by the debris swirling around its event horizon, astonishing the researchers.
The team used observational facilities at the W.M. Keck Observatory in Hawaii and the MMT Observatory in Arizona, as well as remote access to the SoAR telescope in Chile to look at the object's makeup.
"We saw features in the Cow that we have never seen before in a transient, or rapidly changing object", said Raffaella Margutti, an astrophysicist at Northwestern University in Evanston, Illinois.
Margutti noted that science has known from theory that when a star dies it forms either a black hole or neutron star, but neither had ever been observed right after they are born. They found that it was composed of hydrogen and helium. "But The Cow had very little ejecta mass, which allowed us to view the central engine's radiation directly".
In a paper forthcoming in the journal Monthly Notices of the Royal Astronomical Society, they say that the shredded star was a white dwarf - a hot, roughly Earth-sized stellar remnant marking the final state of stars like our Sun. The object flared up quickly and then disappeared nearly as fast.
At first, researchers thought The Cow might be a supernova, but because it was 10 to 100 times brighter that a typical supernova, scientists began looking for alternative explanations.
"In a universe where some phenomena last for millions and billions of years, two weeks amounts to the blink of an eye", the statement said.
"We knew right away that this source went from inactive to peak luminosity within just a few days", Dr Margutti said. "That was enough to get everybody excited because it was so unusual and, by astronomical standards, it was very close by".