Short-duration GRB's and Hypernovas

Article by leading gamma-ray expert,
Dr. Bruce Banner:

When exceptionally large stars collapse at the end of their lifespan, they produce a massive explosion known as a hypernova.  These explosions emit enormous amounts of high-energy radiation, which is typically referred to as long-duration gamma ray bursts, although the process is dissimilar to the normal process of radioactive decay (the range of the energy being well above 10TeV, an energy range exceeding the output of natural radioactive decay.)  It has been estimated that the emission of these gamma ray bursts (GRB) constitute the only single event with that much raw power thus far discovered in the cosmos. 

Though long-duration GRB's are emitted during hypernovas, it has been questioned whether hypernovas can account for short-duration GRB's, since these bursts seem to have no affiliation with massive stars, not appearing in places where such stars have just been formed. More recent studies have dismissed this link, and the question of the origin of short-duration gamma ray bursts is still open, although leading astronomers hypothesize that the mergers of binary neutron stars is a logical explanation for their appearance.

The giant flairs of soft gamma repeaters in nearby galaxies could also account for the appearance of at least a small portion of short-duration GRB's.