Gamma Ray Burst in 1998 Probably Caused by a Supernova Explosion

Caltech astronomers say a burst of cosmic gamma rays--one of the most powerful explosions ever observed--probably originated in a supernova explosion and the formation of a black hole. The observation leaves astronomers more convinced that these brief but brilliant cosmic flashes are generated by the fiery collapse of massive, dying stars.

The short-lived gamma ray burst occurred March 26, 1998. The team reports in today’s Nature that they expected the burst’s afterglow to be quickly replaced by the general brightness of the surrounding galaxy. Instead, light rebrightened “dramatically� at the position of the gamma ray burst, obscuring the galaxy itself. The rebrightening, they say, was caused by the supernova.

--Compiled by Times medical writer Thomas H. Maugh II