Well, they haven't determined anything more than, the two they observed, came from a long way away.
If they all come from so far away, they believe that magnetars cannot be causing them.
The breakthrough came when, for the first time, astronomers were able to accurately pinpoint the locations of two recent short GRBs. They traced the bursts to relatively distant galaxies, bolstering the prevailing theory that the GRBs arise from collisions involving dense stellar corpses, called neutron stars.
...GRBs are volleys of very high energy photons that can originate from any direction in the sky and come in two classes. "Long" bursts last from seconds to minutes and have been found to coincide with powerful supernovae, suggesting they form when massive stars explode and their cores collapse into black holes.
But until recently "short" bursts - lasting just a split-second - have proved frustratingly elusive, disappearing without a trace before researchers could pinpoint or study them.
...Astronomers had suggested flare-ups in highly magnetised neutron stars, called magnetars, might produce short bursts. But these flare-ups can only get so strong before they destroy the stars, putting an upper limit on how far away a magnetar-based GRB can be observed. These bursts occurred about 10 times farther away than this limit, ruling out a magnetar source.
