An artist impression of a black hole swallowing a star (ESO/M.Kornmesser) | SkyNews
An artist impression of a black hole swallowing a star (ESO/M.Kornmesser)

Light burst created as black hole devours a star

Astronomers originally thought they had detected a gamma ray burst, which is the most powerful known source of light in the universe.

Astronomers found a distant supermassive black hole ripping apart a star, creating an intensely bright jet of energy that shoots out radiation and matter at nearly the speed of light.

This phenomenon is a tidal disruption event (TDE) and occurs when stars are shredded by the tidal forces of a nearby black hole. Physicist John Wheeler, who coined the term “black hole,” compared this phenomenon to “a tube of toothpaste gripped tight about its middle” that squirts matter out of both ends.

“We have only seen a handful of these jetted TDEs and they remain very exotic and poorly understood events,” said Nial Tanvir of the University of Leicester, in a statement. Tanvir led the observations using the European Southern Observatory’s Very Large Telescope.

The event, named AT2022cmc, happened when the universe was roughly one-third of its current age. Roughly one per cent of TDEs cause the poles of a black hole to fling jets of radiation and plasma into space. The phenomenon is usually detected in high-energy light, such as gamma rays and X-rays, but this is the first TDE seen in visible light. 

The conditions that allowed astronomers to watch this rarely seen event could help them find similar bursts of energy from other black holes. Astronomers originally thought they had detected a gamma ray burst, which is the most powerful known source of light in the universe. 

The prospect of observing one prompted 21 telescopes around the world to begin collecting data. The only scenario that matched their findings was a rare jetted TDE pointed toward Earth.

“Because the relativistic jet is pointing at us, it makes the event much brighter than it would otherwise appear and visible over a broader span of the electromagnetic spectrum,” said Giorgos Leloudas, an astronomer at DTU Space in Denmark and co-author of this study, in a statement.

Astronomers hope to use lessons learned from the discovery to find more TDEs, and to understand how the jets are created and why they are produced by few TDEs.