You’d assume that the brightest object in the known universe would be a pretty easy thing to discover, but astronomers have only just spotted it. This overlooked show-off is a supermassive black hole with the mass of 17 billion Suns, and counting – it swallows another Sun's worth of material every day, making it also the fastest-growing black hole ever found.
There’s a couple of obvious questions you’re probably asking about this. First, black holes are the blackest things that can exist, and light famously can’t escape its grasp – so how is this one leaking a record-breaking amount of light? Well, it isn’t actually coming from the black hole itself but the swirling disc of material surrounding it, steadily marching into the abyss. With gravitational forces strong enough to warp space and time, that matter is whipped into a frenzy (called a quasar) that shines with the light of 500 trillion Suns.
“It looks like a gigantic and magnetic storm cell with temperatures of 10,000 °C (18,000 °F), lightning everywhere and winds blowing so fast they would go around Earth in a second,” said Associate Professor Christian Wolf, lead author of the study. “This storm cell is seven light years across, which is 50% more than the distance from our solar system to the next star in the Galaxy, Alpha Centauri.”
The second no-brainer question: how has it taken this long to find the brightest thing that will probably ever exist? The answer is a familiar one – space is just incredibly, unfathomably big. No matter how bright your needle is, it’s going to be hard to find on a haystack planet. And this quasar is almost as far away from us as it’s physically possible to get, with its light taking a good 12 billion years to reach us. At that distance, it pretty much just looks like a slightly overachieving star. Just watch this video zooming in on it and you’ll see why.
That’s how it’s eluded detection for so long. Although it’s technically been captured in images dating as far back as 1980, AI models analyzing them didn’t have the data to realize quasars could get that bright, and so wrote it off as a star that was fairly close to Earth. It was only properly identified after being studied closer by Siding Spring Observatory in Australia, and then the Very Large Telescope in Chile.
True space nerds might remember reports in 2019 that another quasar claimed the crown of brightest object in the universe, with the blinding light of almost 600 trillion Suns. But it turns out that one was kind of cheating, exploiting a spacetime loophole called a gravitational lens that magnified its brightness 50 times over. When you take that out of the equation, its light dims to a paltry 11 trillion Suns. At that point, why even bother?
But this new guy is doing all the work the hard way, and that involves eating the equivalent of the Sun every single day. That makes it the fastest-growing black hole ever found too – by comparison, the previous record-holder was a slacker that took two days to eat a Sun. You’ve gotta want it.
The research was published in the journal Nature Astronomy.
