  A standard fireball/afterglow model of a gamma-ray burst relates the event to
a merging neutron star binary, or a neutron star - black hole binary, which
places the events far away from star forming regions, and is thought to have an
energy of ~ 10^51 erg. A hypernova, the death of a massive and rapidly spinning
star, may release ~ 10^54 erg of kinetic energy by tapping the rotational
energy of a Kerr black hole formed in the core collapse. Only a small fraction
of all energy is in the debris ejected with the largest Lorentz factors, those
giving rise to the GRB itself, but all energy is available to power the
afterglow for a long time. In this scenario GRBs should be found in star
forming regions, the optical afterglows may be obscured by dust, and the early
thermal emission of the massive ejecta may give rise to X-ray precursors, as
observed by Ginga.
  The optical and X-ray afterglows of GRBs 970228, 97508, 97828 provide some
evidence that these bursts were located in galaxies, most likely in dwarf
galaxies, in or near star forming regions.
