  Gamma ray bursts (GRBs) are astronomical phenomena detected at highest
energies. The gamma ray photons carry energies on the order of
mega-electronovolts and arrive to us from the point-like sources that are
uniformly distributed on the sky. A typical burst has a form of a pulse that
lasts for about a minute. As the Earth atmosphere is not transparent to the
very high energy radiation, the bursts are detected by means of the telescopes
onboard satellites that are placed on the orbit. The total energetics of GRB
events, which is given by the integrated energy flux by the detector unit area,
implies that we are witnessing very powerful explosions, where an enormously
great power is released within a short time. There is only one way to obtain
such huge energies in cosmos: the disruption of a star.
