Dying Stars May Be Partially Responsible for Gamma Ray Bursts

Astronomers searching for the source of mysterious cosmic flashes known as gamma ray bursts think they have discovered how at least some of the bursts are created--by the explosion of dying stars called supernovas.

Gamma ray bursts--very quick, high-energy flashes of light observable only from space--were discovered just over 25 years ago, and their source is one of the biggest mysteries of astrophysics.

The new window on the phenomenon opened April 25, when a burst of gamma rays occurred about the same time and in the same region of the sky as the most unusual supernova ever observed. Researchers at Caltech, writing in today’s Nature, lay out a scenario by which the supernova could have generated the gamma ray burst. They believe the star explosion ejected a stream of material at close to the speed of light, said astronomer Shri Kulkarni. That’s much faster than is typical of a supernova, and fast enough to produce a gamma ray burst.

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Compiled by Times medical writer Thomas H. Maugh II