A star shredded by a black hole unleashes a jet seen across 8 billion light years

For only the third time ever, astronomers have observed a star being destroyed by a black hole while launching a near–light-speed jet, and for the first time, this phenomenon was caught in optical light at an extreme distance, opening a new window on some of the universe’s most violent events.

One of the most violent events in the universe has now been recorded in unprecedented detail. In 2022, astronomers detected a distant flash so bright and unusual that it initially did not resemble any known class of cosmic explosion. The source, later named AT2022cmc, lay roughly 8 billion light-years from Earth and immediately stood apart from supernovae, gamma-ray bursts, and other familiar transients.

Only two comparable “jetted” tidal disruption events had ever been identified before, and none had been observed at such a vast distance. In this case, the alignment was exceptional: a powerful jet produced by the black hole happened to be pointed almost directly toward Earth, dramatically amplifying its observed brightness.

“This event – AT2022cmc – didn’t seem to match any known type of celestial source,” said Daniel Perley, a reader in astrophysics at Liverpool John Moores University. He explained that most known explosions evolve either much faster, much slower, or appear much bluer in color than what the data revealed.

The observations were pieced together in a study led by Igor Andreoni of the University of Maryland and published in Nature on November 30, 2022. The team concluded that AT2022cmc was an extraordinary type of tidal disruption event, triggered when a star similar in mass to the Sun entered the intense gravitational field of its galaxy’s central black hole.

Tidal disruption events occur when a star passes too close to a supermassive black hole and experiences extreme tidal forces. These forces stretch and tear the star apart, a process often described as spaghettification, converting stellar material into a stream of hot gas.

“Usually, intense gravitational forces tear the star apart, transforming it into a superheated disk of gas which eventually disappears into the black hole,” Perley explained. In most cases, this process produces ultraviolet and X-ray emission that fades over months or years as the gas is gradually accreted.

AT2022cmc behaved very differently. Instead of quietly consuming the stellar debris, the black hole launched a narrow, highly collimated jet of matter moving at close to the speed of light. Some of the infalling material was expelled outward rather than swallowed.

The researchers likened the process to squeezing a toothpaste tube suddenly in the middle, forcing its contents to squirt out from both ends. As the ejected material ploughed into surrounding gas, it generated intense optical, radio, and X-ray emission, producing a luminous afterglow detectable across much of the electromagnetic spectrum.

The event’s luminosity was extreme, greatly exceeding that of any known supernova. Its brilliance was not only a result of immense energy release but also of geometry. Because the jet was aligned nearly along our line of sight, relativistic beaming amplified the signal seen from Earth.

AT2022cmc was located at a redshift of z = 1.19325, placing it firmly at cosmological distance. The light detected in 2022 was emitted when the universe was less than half its current age, making this the most distant optical detection of a jetted tidal disruption event to date.

Such events are extraordinarily rare. “The last one was more than a decade ago,” Perley noted, referring to the previous confirmed examples. The best-studied jetted tidal disruption event prior to AT2022cmc was Swift J1644+57, which was discovered in gamma rays but remained heavily obscured by dust and could not be observed at optical wavelengths.

That contrast makes AT2022cmc particularly important. For the first time, astronomers were able to observe a jetted tidal disruption event initially in optical light, rather than relying on high-energy satellite detections alone. This allowed for rapid, coordinated follow-up observations across a wide range of wavelengths.

The discovery was enabled by the Zwicky Transient Facility in California, a wide-field optical survey designed to detect fast-changing objects in the night sky. Follow-up observations were carried out using the Liverpool Telescope, the Very Large Array in New Mexico, and the Neil Gehrels Swift Space Observatory, among others.

These multi-wavelength data revealed a bright synchrotron afterglow, produced when relativistic electrons spiralled around magnetic field lines in the jet. The presence of this afterglow strongly supported the interpretation of AT2022cmc as a jetted tidal disruption event rather than a conventional explosion.

By analysing four years of survey data from the Zwicky Transient Facility, the team estimated the volumetric rate of on-axis jetted tidal disruption events to be roughly one event per cubic gigaparsec per year. When corrected for jet beaming, this implies that only about 1 percent of all tidal disruption events produce relativistic jets.

The conditions required to launch such jets remain poorly understood. Modelling of AT2022cmc suggests that the central black hole had significant spin, likely greater than about 0.3 on a scale where 1 represents maximal rotation. Black hole spin is thought to help extract rotational energy and power jets, but it cannot fully explain why most disrupted stars fail to produce them.

Other fundamental questions remain unanswered. Astronomers do not yet know how massive the black hole was, what type of galaxy hosted it, or why this particular stellar disruption generated an ultra-fast jet while most do not. These uncertainties highlight how little is still understood about the extreme physics governing black hole accretion.

Despite these mysteries, AT2022cmc marks a turning point. It demonstrates that optical surveys can detect jetted tidal disruption events at cosmological distances and can capture their evolution from the very beginning.

Researchers argue that AT2022cmc can now serve as a prototype for identifying a previously hidden population of jetted tidal disruption events. As time-domain optical surveys continue to expand in depth and cadence, more such events are expected to be uncovered.

Each new detection will help refine models of how supermassive black holes grow, how relativistic jets are launched, and how these rare but powerful events influence their host galaxies across cosmic time.

References;

¹ Cosmic fireworks as distant star ‘squeezed’ by massive black hole – Liverpool John Moores University – November 30, 2025

² A very luminous jet from the disruption of a star by a massive black hole – Igor Andreoni et al. – Nature – https://doi.org/10.1038/s41586-022-05465-8 – November 30, 2025

Reet Kaur

I’m a science journalist and researcher at The Watchers, contributing to the Epicenter edition, where I cover peer-reviewed scientific research and emerging discoveries across Earth and space sciences. With a background in astronomy and a passion for environmental science, I’ve worked in shark and coral conservation in Fiji, conducting reef and shark-behavior research, contributing to mangrove restoration, and earning PADI Open Water and Coral Reef Certifications. I bring a blend of scientific rigor and storytelling to illuminate the discoveries shaping our planet and beyond.

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