A huge black hole has just been discovered that is about 13 billion light-years old – almost as old as the universe itself. The find of this supermassive black hole is puzzling astronomers because they can't figure out how this black hole was formed so early in the universe's history.
The black hole, which is in the center of the quasar ULAS J1342+0928, is about 800 million times more massive than our sun. Scientists previously thought that black holes grow by picking up mass from the environment around them. But this black hole arose in a universe that was only 690 million years old — not nearly enough time to accumulate the mass needed to grow so big.
"It has an extremely high mass, and yet the universe is so young that this thing shouldn’t exist," Robert Simcoe, an astrophysicist at the Massachusetts Institute of Technology, said in a statement. "So there must be another way that it formed," he added. "And how exactly that happens, nobody knows."
Besides revealing a mystery about black hole formation, the new discovery sheds more light (so to speak) on when the first stars formed in the universe. Before first starlight, the universe was dominated by neutral hydrogen atoms.
As more stars and galaxies filled the void, their radiation began to energize the hydrogen, allowing the electrons bound to the nucleus to recombine and generate other chemical reactions. But when the black hole was formed, the universe was comprised of about 50 percent ionized (or energized) hydrogen and 50 percent neutral hydrogen.
"It’s a moment when the first galaxies emerged from their cocoons of neutral gas and started to shine their way out," Simcoe said. "This is the most accurate measurement of that time and a real indication of when the first stars turned on."