As a black hole shredded a star, NASA’s Hubble watched
The invisibility of a black hole could be considered its greatest strength. Across the fabric of space, these silent beasts drink every drop of light that enters their gravitational pulses, intercepting those rays from the observable universe and waiting in the darkness for a helpless star to appear. Then they attack.
Now scientists have announced that NASA’s Hubble Space Telescope has captured what’s next in one such cosmic nightmare — otherwise known as a tidal disturbance event, where a black hole eats its prey or “accretes” a star. Astronomers shared the news Thursday at a meeting of the American Astronomical Society.
“Usually these events are difficult to observe. You might get a few observations early in the perturbation when it’s really bright,” says Peter Maksym of the Center for Astrophysics | Harvard & Smithsonian, said in a statement. “We saw this early enough to be able to observe it in these very intense black hole accretion stages.”
Caught in the deadly gravitational embrace of an abyss, this star’s spherical shape has been aggressively mutated into a twisted strand of glowing matter. Before Hubble’s glazed eyes, the star was viciously ripped apart until it looked like a distorted whirlpool of pixie dust orbiting its predator, leaving a flaming tail to illuminate the otherwise empty void of space.
Appropriately, this is sometimes referred to as a black hole’s “spaghettizing” matter, because even the strongest objects unfortunate enough to get too close to the gravitationally extreme pit are reduced to thin, crusty shreds.
This series of artistic illustrations shows how a black hole can engulf a passing star. 1. A normal star passes a supermassive black hole at the center of a galaxy. 2. The star’s outer gases are drawn into the black hole’s gravitational field. 3. The star is shredded as tidal forces pull it apart. 4. The stellar remnants are drawn into an annular ring around the black hole and eventually fall into the black hole, releasing a tremendous amount of light and high-energy radiation.
NASA, ESA, Leah Hustak (STScI)
Meanwhile, the black hole gobbled its donut from a star — scientifically called a torus at this point — drawing in the tormented orb’s gases while spewing out material as if they were bones from a tasty chicken meal. For context, this torus is assumed to be the size of our entire solar system.
“We’re looking somewhere on the edge of this donut. We see a stellar wind from the black hole sweeping across the surface projected towards us at a speed of 20 million miles per hour,” Maksym said, meaning 3 percent the speed of light.
That’s huge not only because it’s absolutely spectacular — but also because galaxies with quiescent or dormant black holes like the one analyzed by Hubble are only expected to devour a star every 100,000 years.
“We’re really still dealing with the event,” Maksym said.
A simulation of a star being blown apart after approaching a black hole.
DESY, science communication laboratory
But it didn’t look like something out of a Hollywood movie
To be clear, Hubble didn’t literally take pictures of everything that happened in real time. So no, this black hole didn’t look like the iconic interstellar Leviathan from the scope’s view.
I mean, after all, this whole situation happened about 300 million light years from Earth — which also means it happened about 300 million years ago, but light from that event just reached our planet, so we see it in what we do see call “the present”.
However, what Hubble did to capture this scene allows scientists to deduce pretty accurately what it would look like if we could somehow watch the details unfold like a movie.
The telescope’s strong UV sensitivity was able to study light from the tattered star that has journeyed to Earth over thousands of years, and astronomers have been able to track basically all of these light signals to find out how the star warps, crumples and crumples did when he went down.
You can watch a preview of the event as calculated by the team below.
“Given the observation time, there are still very few tidal events observed in ultraviolet light. It’s really unfortunate because there’s a lot of information to be gained from the ultraviolet spectra,” said Emily Engelthaler of the Center for Astrophysics | Harvard & Smithsonian, said in a statement. “We’re excited because we can get these details of what the debris is doing. The tidal event can tell us a lot about a black hole.”
Officially named AT2022dsb, this event was captured on March 1, 2022 by a network of ground-based telescopes called the All-Sky Automated Survey for Supernovae.
That piqued the interest of Hubble astronomers, who immediately tried to get ultraviolet readings across the violent tidal disturbance for as long as possible, to gather as much information as possible about the star’s evolution as it was being torn apart by the black hole.
“You shred the star and then it has this material that finds its way into the black hole. And so you have models that you think you know what’s going on, and then you have what you actually see,” Maksym said. “This is an exciting place for scientists: right at the intersection of the known and the unknown.”