In one scenario, proposed in 1986 by Bohdan Paczy nski of Princeton University, two neutron stars or a neutron star and a black hole orbit ever more tightly and eventually unite in a passionate but ruinous embrace. Stan E. Woosley of the University of California at Santa Cruz suggested another possibility in 1993. Despite some observers' initial claims, the brightness of the bursts may not be enough to decide between these models. Both lead to the same kind of object, a black hole surrounded by a ring of debris. Pinpointing the bursts' locations within their galaxies may supply clues.
Neutron stars wander far from their places of birth before merging, whereas hypernovae stay put.
But there is a third possibility. The diversity of these latest bursts, Woosley says, suggests that each model accounts for some bursts.