Astronomers Discover Oldest Black Hole Ever Observed, and It’s Feasting

Astronomers have discovered what might be the oldest black hole ever observed, challenging their understanding of how these fascinating and inescapable regions of space form and grow.

This supermassive black hole, several millions times bigger than our Sun, is thought to be more than 13 billion years old, or about 400 million years after the Big Bang—a surprising age given that scientists typically think it takes billions of years for a black hole to grow this large.

An international team of researchers found the black hole using the James Webb Space Telescope (JWST) and reported their findings on Wednesday in Nature. 

Astronomers aren’t able to glimpse black holes directly. Instead, they look for the tell-tale glow of extremely hot gasses swirling around their edges, known as accretion discs. The black hole at the focus of this study sits inside a young galaxy called GN-z11. It’s one of the brightest of its age, so much so that the study’s authors describe it as “exceptionally luminous.”

One theory that tries to explain this glow attributes it to how the black hole devours dead stars and other material from the galaxy so voraciously—at five times the theoretical limit. “Very early galaxies were extremely gas-rich, so they would have been like a buffet for black holes,” said study co-author, Roberto Maiolino, an experimental astrophysicist from the University of Cambridge, in a statement.

The problem (for the host galaxy, at least) if the ravenous-black hole theory holds, is that the black hole would eventually kill its host. When black holes eat too much gas too quickly, it pushes that gas away at ultra-high speeds, which stops new stars from forming. The black hole essentially eats its host galaxy to death. 

Another explanation for how the black hole grew so massive so quickly could be that some black holes are simply born big, from the direct collapse of huge clouds of gas rather than the usual dead stars. 

Whatever the case may be, black holes like the one inside GN-z11 are making researchers rethink how these regions of space form and evolve. “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 wasn’t involved in this latest study, told The Guardian. 

Physicists have previously put forward several scenarios for the origins of black holes, but because there hasn’t been a telescope powerful enough to glimpse that far back into time, they haven’t been able to test these ideas directly. That changed with the JWST.  

“Before Webb came online, I thought maybe the universe isn’t so interesting when you go beyond what we could see with the Hubble Space Telescope,” said Maiolino. “But that hasn’t been the case at all: the universe has been quite generous in what it’s showing us, and this is just the beginning.”

In recent years, researchers have discovered several bright galaxies from the start of the universe using JWST. This new scenario for how GN-z11’s black hole grew so big, and why the galaxy itself is so bright, could explain these other galaxies too. What’s more, it could help explain how the universe went from being a hot, dark soup of particles to one containing the first blips of light from stars.