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Black hole caught eating a star

A powerful blast of gamma rays may have been caused when a star fell into a large black hole

A BLACK hole鈥檚 gruesome feast may explain an unusual blast of gamma rays seen in 2006. Long-lasting bursts like this one, which was named GRB 060614, are usually thought to mark the collapse of a massive star that has run out of fuel. But GRB 060614 lacked the usual optical fireworks, and might instead be the result of a large black hole, thousands of times the mass of the sun, dismembering and devouring a star.

A star approaching such a large black hole would be squashed into a pancake by the black hole鈥檚 gravity, before ripped into a stream of debris. Most of this material would be quickly gulped down by the black hole, but in the process some would also squirt out in high-speed jets, producing copious gamma rays, says a team led by Ye Lu of the National Astronomical Observatories in Beijing, China, in a paper that will appear in The Astrophysical Journal.

There is wide agreement that GRB 060614 was an unusual gamma-ray burst, but Enrico Ramirez-Ruiz of the University of California, Santa Cruz, who was not involved in the study, is doubtful that a black hole devouring a star explains it.

That process fails to match the energy of the observed blast, he says.