Astronomers using the James Webb Space Telescope (JWST) have detected the earliest known black hole. Located more than 13 billion light-years away, it dates to a mere 400 million years after the Big Bang.
The black hole lies at the center of a galaxy called GN-z11, which, at the time of its discovery in 2016, was the oldest galaxy ever spotted. But what has shocked researchers about this early black hole is its large size.
“It’s not its age that is surprising, it is the fact that it is already so big so early in the universe, which is difficult to explain with standard theories,” Roberto Maiolino, a co-author of the study and astrophysicist at the University of Cambridge in the United Kingdom, tells Newsweek’s Jess Thomson.
Black holes are incomprehensible quantities of matter stuffed into a relatively small space. Because they’re so dense, their gravitational pull is powerful enough to suck in anything that comes close, including light. As a result, black holes can’t be observed directly—scientists can only see their effect on their surroundings.
In the case of the galaxy GN-z11, researchers had already noticed it was unusually bright. To be so luminous, “it would have required a large number of stars packed in such a small volume,” Maiolino tells NPR’s Ari Daniel.
But observations from Webb revealed the galaxy’s bright light doesn’t come from stars—instead, it’s from hot gas swirling around the black hole as it gets sucked inside. The findings were published Wednesday in the journal Nature.
“These authors have made a persuasive case that there is a black hole,” Priyamvada Natarajan, an astrophysicist at Yale University who did not contribute to the findings, tells NPR.
In November, Natarajan and other astronomers announced the discovery of what was, at the time, the earliest known black hole, dating to 470 million years after the Big Bang. The Webb telescope played a role in that discovery as well.
That black hole was also unexpectedly massive—between 10 million and 100 million times the mass of our sun.
“It’s just really early on in the universe to be such a behemoth,” Natarajan told Marcia Dunn of the Associated Press at the time.
The newly discovered black hole is roughly 1.6 million times as massive as our sun, according to Live Science’s Ben Turner.
Scientists previously thought that black holes gradually grew to the massive sizes they are today, according to a statement from the University of Cambridge. But if the newly discovered black hole had grown according to the standard models, it would take about a billion years to reach its large size. So, for the object to be as big as it is during the young universe, it would have had to either start out much larger than thought or grow much more quickly than expected.
“This black hole is essentially eating the [equivalent of] an entire sun every five years,” Maiolino tells NPR. “It’s actually much higher than we thought could be feasible for these black holes.”
According to the leading theories, for early black holes to become so massive that quickly, they might have formed from the sudden collapse of giant gas clouds or from many stars and black holes merging together, writes Live Science.
“Understanding where the black holes came from in the first place has always been a puzzle, but now that puzzle seems to be deepening,” Andrew Pontzen, a cosmologist at University College London who was not involved in the research, told the Guardian’s Hannah Devlin in December, when the paper was published as a preprint. “These results, using the power of JWST to peer back through time, suggest that some black holes instead grew at a tremendous rate in the young universe, far faster than we expected.”