When certain stars collapse, they release overwhelming blasts of energy called gamma-ray bursts – the most powerful explosion in the universe. But the cosmic leftovers of these violent outbursts have been a mystery — until now.

Two new studies suggest that when gamma-ray bursts explode, some can leave behind black holes like cosmic gravestones, while others may end up as spinning neutron stars.

Gamma-ray bursts occur when some massive stars reach the ends of their lives and exhaust their supplies of fuel for nuclear fusion in their cores. Without the pressure from fusion pushing outward, gravity wins.

In the ensuing dramatic collapse, a flood of high-energy, short-wavelength gamma-ray light is released. They are sometimes associated with supernovas – another explosive way stars die – but are separate events. [ YAHOO NEWS ]