Friday, April 8, 2011

Powerful Space Explosion May Herald Star's Death By Black Hole

A huge, powerful star explosion detonated in deep space last week — an ultra-bright conflagration that has astronomers scratching their heads over exactly how it happened.

The explosion may be the death cry of a star as it was ripped apart by a black hole, scientists said. High-energy radiation continues to brighten and fade from the March 28 blast's location, about 3.8 billion light-years from Earth in the constellation Draco.

Astronomers say they've never witnessed an explosion so bright, long-lasting and variable before, according to NASA officials.

The explosion looks like a gamma-ray burst the most powerful type of explosion in the universe, which usually mark the destruction of a massive starbut the flaring emissions from these dramatic events never last more than a few hours, researchers said.

"We know of objects in our own galaxy that can produce repeated bursts, but they are thousands to millions of times less powerful than the bursts we are seeing now," said Andrew Fruchter, of the Space Telescope Science Institute in Baltimore, in a statement today (April 7). "This is truly extraordinary."
And:
"The fact that the explosion occurred in the center of a galaxy tells us it is most likely associated with a massive black hole," said Neil Gehrels, the lead scientist for Swift at NASA's Goddard Space Flight Center, in a statement. "This solves a key question about the mysterious event."
Also:
Astronomers have detected stars disrupted by supermassive black holes before, but none have shown the X-ray brightness and variability seen in GRB 110328A, which has flared repeatedly. Since April 3, for example, it has brightened by more than five times.

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