A powerful gamma-ray flash that was detected at the center of a galaxy 3.8 billion light-years away, in the constellation Draco, has been attributed to a star being ripped apart by a black hole. The intense flash was initially considered to be a burst of gamma rays from a collapsing star, one of the most powerful types of explosions in the universe. However, its continuing high intensity after two months points to a much rarer phenomenon.
The research of Andrew Levan and co-workers, University of Warwick, UK, shows that a massive black hole at the very center of the galaxy has pulled in a star about the size of our sun and ripped it apart by tidal disruption. The spinning black hole then created two jets of high energy X-rays and gamma-rays, one of which pointed toward earth, allowing the event to be observed. Subsequent intense flares are assigned to further chunks of the star falling into the black hole.
This particular black hole has not been sating up matter around it like some other active black holes in the universe which makes this a rare event expected to occur once every 100 million years.
Image: © University of Warwick/Mark A. Garlick
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