Astronomers have caught a supermassive black hole eating a giant star in the biggest and brightest example of this powerful event ever seen. It could be the missing link that helps us understand mysteriously bright cosmic objects in the centres of some active galaxies.
When a black hole gobbles up a star, it doesn鈥檛 happen in one titanic gulp 鈥� instead, the star is torn apart in a violent process called a tidal disruption event (TDE). These are some of the brightest events in the sky. at the Harvard-Smithsonian Center for Astrophysics in Massachusetts and his team have now found one that is nearly 10 times as bright as any we have seen before.
This TDE, called AT2023vto, is so bright scientists originally thought it was a supernova. However, when Berger and his team conducted follow-up observations and more analysis of the original data, they found it was a much closer match to a star being ripped limb from limb. 鈥淚t鈥檚 much more energetic than any TDEs we鈥檝e seen before, and yet it behaves exactly like all of the other tidal disruption events,鈥� says Berger.
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The researchers鈥� models showed AT2023vto was caused by a star about nine times as massive as the sun falling into a black hole about 10 million as massive as the sun. Finding such a huge star so close to a supermassive black hole is rare.
鈥淎 star like this one has a lifetime of only about 10 million years or so, so in all likelihood it had to have formed in the vicinity of the supermassive black hole,鈥� says Berger. That is a fast-paced and complex environment, so studying events like this could help us understand the possibility of star formation there.
It could also help us figure out strange objects called ambiguous nuclear transients (ANTs). These are bright flashes from the centres of certain galaxies 鈥� some researchers have suggested these may be a new type of TDE involving extremely massive stars. If that is ANTs鈥� true identity, then this cosmic cataclysm could be the missing link between them and the less-extreme TDEs already familiar to astronomers.
arXiv
