In 2018, astronomers were shocked to find a bizarre explosion in a galaxy 200 million light-years away. It wasn’t like any normal supernova seen before—it was both briefer and brighter. The event was given an official designation, AT2018cow, but it soon went by a more jovial nickname: the Cow.
The short-lived event—known as a transient—defied explanation. Some thought it might be a star being torn apart by a nearby black hole, but others favored a “failed supernova” scenario, where a black hole quite literally eats a star from the inside out. To find out for sure, they needed to find more Cow-like events.
More than two years later, they got one.
Beginning on October 12, 2020, telescopes watched as something in a galaxy 3 billion light-years away became incredibly bright, then disappeared from view. It behaved almost identically to the Cow, astronomers reported in a paper posted to the online preprint site arXiv.org last week, leading them to conclude that it must be the same type of episode. In keeping with tradition, it was given its own animal-inspired name: the Camel.
These astronomers were able to watch the course of this event, from a bright, explosive start, to what likely is a failed star collapsing into a black hole. In real time…happening 3 billion years ago.