Like many doctors, Shri Kulkarni and Kris Stanek carry pagers to alert them to emergencies. But they are not physicians; they are astronomers. When their pagers ring, there has been a crisis somewhere in the universe―a cataclysmic explosion with the power of ten thousand trillion suns. Gamma rays provide more than just information about Mars (see previous story). They also speak of these events, which are known as gamma-ray bursts, that occur in the farthest reaches of space. Whenever a gamma-ray burst happens, Dr Stanek and Dr Kulkarni rush to contact whichever of their colleagues are using large telescopes at the time. Their goal is to commandeer those telescopes quickly enough to study the fading light from the fireball that follows the gamma rays, in order to solve the long-standing mystery of what causes the explosions. That mystery was the subject of a recent conference entitled "The Brightest Explosions in the Universe", held in Cambridge, Massachusetts. And, as the conference heard, by studying a burst that took place last November, teams led by Dr Kulkarni, of the California Institute of Technology, and Dr Stanek, of the Harvard-Smithsonian Centre for Astrophysics, in Cambridge, claim to have found the trigger for some of them.
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