Los
Angeles Times: For the first time, astronomers say they've
borne witness to a supermassive black hole consuming a star,
writes Amina Khan for the
Los Angeles Times. On 28 March a detector on the
Earth-orbiting
Swift observatory picked up a sudden burst of
radiation from a point in the constellation Draco, 4.5 billion
light-years away. Typically the gamma-ray bursts that
Swift was designed to detect are one-time events
caused by an exploding star. In this instance, however,
subsequent bursts were detected from the same spot, which
convinced the researchers that the origin was not a supernova
exploding. David Burrows of the Pennsylvania State University
and colleagues have proposed instead that a star about the same
size as our Sun ended up too close to the black hole, which
caused the side of the star nearest the black hole to stretch
toward it, in much the same way that the Moon causes the tides
on Earth. As the gravitational forces shredded the star, chunks
of its plasma streamed toward the black hole, and some of the
material was expelled into a jet of high-energy radiation. That
jet was likely responsible for the mysterious burst detected in
March. The astronomers say they were lucky to witness the
event—the jet of radiation just happened to blast
straight toward
Swift, like a flashlight beamed in the face. Their
results
were published yesterday in
Nature.
