Researchers believe they might have an explanation for an incredibly bright event that took place in a distant dwarf galaxy. Scientists observed it last June when the object in question lit up and then faded over the course of 16 days, and it has continued to spark interest and debate. Based on the data collected at the time, a number of researchers now think the event was the creation of either a black hole or a neutron star.
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. “We know from theory that black holes and neutron stars form when a star dies,” Northwestern University Professor Raffaella Margutti said in a statement, “but we’ve never seen them right after they are born. Never.” Margutti headed Northwestern University’s investigation of the bright event and presented her team’s findings at the American Astronomical Society meeting. The work will also be published in the Astrophysical Journal.
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. They also used a number of observatories to study The Cow, viewing it with X-rays, hard X-rays, radio waves and gamma rays, all of which allowed them to get a more comprehensive look at The Cow.
And a few lucky breaks helped out as well. The dwarf galaxy that houses The Cow is around two hundred million light years away, which may seem like a lot, but is pretty close by astronomical standards. Plus, there was less than usual amounts of material surrounding The Cow during the event, allowing astronomers to see through it to observe The Cow’s “central engine.”
Other researchers involved in the work support the notion of the formation of a black hole or a neutron star. But some believe the data suggests The Cow is the result of a black hole engulfing a white dwarf.