An “extraordinary flash” seen in the sky earlier this year was caused by a distant star that was “squashed like a toothpaste tube” by a supermassive black hole, astronomers said.
In what experts describe as one of the most violent events in the universe, the unfortunate star met its doom after getting too close to this black hole, setting off a fairly bright light show – with more light than a trillion suns – to be detected by instruments on Earth.
Astronomers have observed other similar tidal disruption events (TDEs) before – in which a passing star is torn apart by the tidal forces of a black hole – but experts say this one, dubbed AT2022cmc, is the brightest of always.
At more than eight billion light-years away, it is also the farthest TDE ever detected, more than halfway across the universe.
The scientists said their findings, published in two papers in the journals Nature and Nature Astronomy, could help shed new light on how supermassive black holes feed and grow.
Dr Matteo Lucchini, a postdoc at the MIT Kavli Institute for Astrophysics and Space Research in the US, and one of the authors of the Nature Astronomy paper, said: ‘We know there is one supermassive black hole per galaxy, and they formed very rapidly in the first million years of the universe.
“This tells us that they feed very quickly, even if we don’t know how the feeding process works.
“So, sources like a TDE can actually be a very good probe into how that process happens.”
Dr Daniel Perley, a reader in astrophysics at Liverpool John Moores University who co-authored the Nature paper, said AT2022cmc was an “extraordinary” type of TDE that “did not appear to match any known type of celestial source.” ”.
He said: ‘The best-known types of outbursts are much faster, much slower, or much bluer in color than the data infers.
“Usually, intense gravitational forces tear the star apart, turning it into a disk of superheated gas that eventually disappears into the black hole.
“However, in this case, something happened that ejected matter almost at the speed of light into space.
“The way we describe it is like a tube of toothpaste being suddenly squeezed in the middle causing the contents to squirt out from both ends.
“Then, when the material collides with the surrounding gas, the intense optical, radio, and X-ray emission is produced.”
Debris from the crushed star created a powerful jet, resulting in what scientists say is an “extraordinary flash” detected by the team at the Zwicky Transient Facility in California during a routine all-sky survey in February.
Experts believe this bright jet was aimed directly at Earth, allowing instruments and telescopes to record this event in detail.
Dr Dheeraj Pasham, also of the MIT Kavli Institute for Astrophysics and Space Research, who is lead author of the Nature Astronomy paper, said this team was able to ‘capture this event at the very beginning, within a week from the beginning of the black hole to feed on the star”.
Astronomers say TDEs like AT2022cmc are rare – the last time scientists discovered one of these jets was well over a decade ago.
It is also the first time that a “jetted TDE” jet has been detected during an optical survey.
Dr. Perley said, “Until now, the small number of jet TDEs that are known were initially detected using high-energy X-ray and gamma-ray telescopes.”
Several instruments from around the world, including the Liverpool Telescope in Spain and the European Southern Observatory’s Very Large Telescope in Chile, were used to learn more about the event.
The analysis showed AT2022cmc was hot — about 30,000 degrees — which is typical for a TDE, according to the astronomers.
However, it’s still a mystery why some TDEs launch jets while others don’t.
As more powerful telescopes are launched, astronomers say they may be able to observe more TDEs and get some answers.
Dr. Lucchini said: “We expect many more of these TDEs in the future.
“Then we might be able to finally tell how exactly black holes fire these extremely powerful jets.”