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Brightest X-Ray Burst

June 20, 2011

One year ago tomorrow, the screams of a dying star in a distant galaxy reached Earth. They produced the brightest X-ray burst scientists have ever seen from beyond our own galactic neighborhood.

The explosion was all the more incredible when you consider its immense distance: five billion light-years. Yet even from that great distance, the explosion was so bright that it temporarily blinded the telescope aboard the orbiting Swift X-ray observatory.

The radiation most likely was created when a massive star reached the end of its life.

The star owed both its birth and its death to the same force: gravity. Millions of years earlier, gravity had caused a large cloud of gas and dust to collapse and become a massive star. The star shone brilliantly, generating energy that pushed outward, balancing the inward-pulling force of gravity. The battle between light and gravity continued throughout the star's entire life.

But last year, gravity finally won out. The star ran out of fuel, so it could no longer generate energy in its core. The core collapsed to form a black hole, and the star's outer layers exploded.

Because the star was five billion light-years from Earth, the star actually exploded five billion years ago -- about half a billion years before Earth was even born. The X-ray burst reached Earth only after our planet had spawned intelligent life capable of launching X-ray telescopes like the one aboard Swift.


Script by Ken Croswell, Copyright 2011


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