The Gamma-Ray Bursts and the SWIFT Mission

Abstract

Gamma-Ray bursts have been a mystery puzzling the astronomers since their accidental discovery in the late sixties. In the short time of their duration they become the most luminous source of the universe, and then, after a gradual fading that can last for one year, they disappear. In the last three years, after the first detection of the so-called afterglows, the whole phenomenon has been put in a new perspective and there is now a general scenario that explains many of the basic properties of the bursts. Still, however, the open questions are more than the solved ones. Here we discuss the physics of the fireball model together with the fundamental observations that drove us to the formulation of this model. We finally describe the NASA Swift mission which has been schedule to fly in the 2003.