Brilliant Demise

StarDate: March 19, 2009

You are missing some Flash content that should appear here! Perhaps your browser cannot display it, or maybe it did not initialize correctly.

audio/mpeg icon

Anyone who spends much time looking into the night sky is going to see some quick flashes of light. Most of them are meteors or satellites -- streaks of light that are no more than a few hundred miles away. But anyone who was looking into the constellation Bootes one year ago would have seen a completely different sort of flash -- one that emitted its light long before Earth was born.

The flash was a gamma-ray burst. It marked the titanic explosion of a star that was much heavier than the Sun. The star could no longer produce energy in its core, so the core collapsed to form a black hole. The outer layers exploded with tremendous force, creating a supernova. This explosion was so powerful that, for about 30 seconds, it was bright enough to see with the unaided eye.

The star's destruction was also accompanied by "beams" of gamma rays. Powerful magnetic fields directed the beams into space from the star's poles. Earth lined up directly along one of those beams, which flashed us with gamma rays like a cosmic headlight -- a beam that was detected by an orbiting satellite.

The star's death was the brightest object ever detected. For a few seconds, it outshone every other star in the universe combined. Observations with the Hobby-Eberly Telescope at McDonald Observatory showed that the star was 7.5 billion light-years away. That means the star exploded 7.5 billion years ago -- three billion years before Earth was born.

Script by Damond Benningfield, Copyright 2009

For more skywatching tips, astronomy news, and much more, read StarDate magazine.

The one constant in the Universe: StarDate magazine


©2014 The University of Texas McDonald Observatory