Fastest-growing black hole in the universe eats the equivalent of one sun per day

This artist’s impression shows how ULAS J1120+0641, a very distant quasar powered by a black hole with a mass two billion times that of the Sun, may have looked. This quasar is the most distant yet found and is seen as it was just 770 million years after the Big Bang. This object is by far the brightest object yet discovered in the early Universe. Credit: ESO/M. Kornmesser

Astronomers have come across a monstrously large black hole with a gargantuan appetite. Each passing day, the insatiable void known as J2157 consumes gas and dust equivalent in mass to the sun, making it the fastest-growing black hole in the universe.

The sheer scale of J2157 is almost unfathomable, but we can try pinning some numbers on it nevertheless.

According to Christopher Onken, an astronomer at the Australian National University who was part of the team that originally discovered the object in 2019, J2167 is 8,000 times more massive than the supermassive black hole found at the heart of the Milky Way. That’s equivalent to 34 billion times the mass of the Sun.

In order for Sagittarius A*, the Milky Way’s supermassive black hole, to reach a similar size, it would have had to gobble two-thirds of all the stars in the galaxy.

For their new study, astronomers turned to ESO’s Very Large Telescope in Chile to get a more accurate assessment of the black hole‘s mass. The researchers already knew they were dealing with a black hole of epic proportions, but the final results surprised everyone.

“We knew we were onto a very massive black hole when we realized its fast growth rate,” said team member Dr. Fuyan Bian, a staff astronomer at ESO. “How much black holes can swallow depends on how much mass they already have. So, for this one to be devouring matter at such a high rate, we thought it could become a new record holder. And now we know.”

Although black holes can’t be imaged directly because they don’t let light escape, J2157 is actually classed as a quasar, or “quasi-stellar radio source” — extremely bright objects powered by black holes at least a billion times as massive as our sun.

The bright signal of the quasar is formed by particles of dust and gas accreting around the edge of the supermassive black hole that are accelerated away at almost the speed of light. Practically, the black hole acts like an extremely powerful natural particle accelerator.

Luckily for us, the black hole is located many billions of light-years away. But this also means that astronomers are measuring J2157’s gravitational influence as it appeared in the distant past when the universe was still very young.

“We’re seeing it at a time when the universe was only 1.2 billion years old, less than 10 percent of its current age,” Dr Onken said. “It’s the biggest black hole that’s been weighed in this early period of the Universe.”

Since then, J2157 likely grew even bigger, perhaps merging with several other black holes across the eons.

“With such an enormous black hole, we’re also excited to see what we can learn about the galaxy in which it’s growing,” Dr Onken said. “Is this galaxy one of the behemoths of the early Universe, or did the black hole just swallow up an extraordinary amount of its surroundings? We’ll have to keep digging to figure that out.”

The findings appeared in the Monthly Notices of the Royal Astronomical Society.