Scientists have just discovered a supermassive black hole that existed surprisingly early in the history of the universe, and the puzzling find is shedding new light on when the first stars blinked on.
Astronomers spotted the black hole, the most distant ever found, sitting inside a bright object so far away that the light had been traveling for 13 billion years before reaching Earth.
The monster black hole looks to be about 800 million times as massive as our sun, and astronomers can't understand how such a behemoth could have already formed just 690 million years after the Big Bang, when the universe was just 5 percent of its current age.
"We expected as we looked further back into time that the black holes would be smaller and smaller because they hadn't had as much time to grow," says Rob Simcoe, an astrophysicist at the Massachusetts Institute of Technology and one of the authors of a newly published research paper in Nature. "What was surprising here was that this one seemed to be fully formed even though the universe was very young at this period in time."
In addition, he says, it looks like this black hole formed in a cosmic environment that was only just starting to be affected by light from the first stars.
"The moment when the first stars turned on is when our universe filled with light," says Simcoe, who explains that when this light leaked out of the first galaxies, it interacted with the surrounding matter and changed its properties. "We have an estimate now, with about 1 to 2 percent accuracy, for the moment at which starlight first illuminated the universe."
This was a major moment in history, he adds: "It's when the universe first started manufacturing chemicals other than hydrogen and helium, all the elements of the periodic table were starting to be formed."
The black hole was detected by Eduardo Bañados of the Observatories of the Carnegie Institution for Science, who was scouring surveys of the sky to look for ancient objects like this one.
"He really deserves all the credit for finding that needle in the haystack," Simcoe says.