Astronomy of cosmic gamma-ray burst

The gamma-ray bursts (GRBs) are one of the greatest mysteries of the high energy astrophysics. After their discovery in 1967, more than two thousands events have been observed by several experiments, but still today no astrophysicist can surely state what the GRBs are and where they come from. Before the advent of BeppoSAX only a statistical approach to the problem gave some results. The first, but still recent, achievement of such investigations are the isotropy of the GRBs arrival directions in the sky, and the paucity of weak events with respect to a homogeneous spatial distribution. The BeppoSAX satellite, not specifically designed for GRB observations, carries the right instrumentation for a novel approach to the GRB problem. It has been able to detect, localize and follow-up few GRBs on very short time-scales. This allowed for the discovery of the first X-ray afterglow of a GRB. The precision and rapidity of the detection, and the wide dissemination of information has permitted other observatories to point the directions, discovering the first optical/radio afterglow, and the measurement of its distance and size of a host galaxy.