Astronomers have witnessed the final moments of a star being devoured by a supermassive black hole – and it’s not pretty.
A blast of light from 215 million light years away from Earth allowed astronomers to study the “tidal disruption event” in unprecedented detail.
Stars that wander too close to vast supermassive black holes are shredded (“spaghettified”) into thin streams of material, which are in turn devoured, releasing flashes of light.
Matt Nicholl, a Royal Astronomical Society research fellow and lecturer at the University of Birmingham, said: “The idea of a black hole ‘sucking in’ a nearby star sounds like science fiction.
“But this is exactly what happens in a tidal disruption event.”
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Thomas Wevers, a European Space Observatory (ESO) fellow in Santiago, Chile, said: “When an unlucky star wanders too close to a supermassive black hole in the centre of a galaxy, the extreme gravitational pull of the black hole shreds the star into thin streams of material.”
Although powerful and bright, up to now astronomers have had trouble investigating this burst of light, which is often obscured by a curtain of dust and debris.
The researchers said that when a black hole devours a star, it launches a powerful blast of material outwards, that can obstruct our view.
But they were able to get a clear, unobstructed view, as they caught the event extremely early.
“Because we caught it early, we could actually see the curtain of dust and debris being drawn up as the black hole launched a powerful outflow of material with velocities up to 10,000 kilometres per second,” said Kate Alexander, NASA Einstein fellow at Northwestern University in the US.
“This unique ‘peek behind the curtain’ provided the first opportunity to pinpoint the origin of the obscuring material and follow in real time how it engulfs the black hole.”
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The team carried out observations of AT 2019qiz, located in a spiral galaxy in the constellation of Eridanus, over a six-month period as the flare grew in luminosity and then faded away.
“Several sky surveys discovered emission from the new tidal disruption event very quickly after the star was ripped apart,” said Wevers.
“We immediately pointed a suite of ground-based and space telescopes in that direction to see how the light was produced.”