In the fleeting glory of their detonation, gamma-ray bursts release more energy than any explosion since the Big Bang and briefly illuminate the most distant corners of the universe. Now astronomers have found that they possess a property that will allow them to be studied more effectively despite being beyond the reach of conventional telescopes.
Gamma-ray bursts were discovered in the late 1960s but only in the past two years have they been found to originate in the very distant, early universe. They are observed randomly several times a day and are thought to be caused by either the collapse of a very massive star or the collision of two neutron stars. Many occur further away than the farthest supernovae and quasars astronomers are currently able to detect.
A study by a team of American astronomers led by Jay Norris, an astrophysicist at Nasa's Goddard Space Flight Center in Maryland, US, has found that time lags between the arrival of different energy gamma rays from a single burst are linked to its distance.
According to the research, which is to be published in the Astrophysical Journal, this will allow astronomers to gauge the position of a burst, and hence allow them to start exploring one of the earliest and hitherto unknown epochs of the cosmos.
"If our finding holds up, this could be a new window on the distant universe," said Dr Norris.
A new era for astronomy in X and gamma-ray wavelengths is set to open a week today with the launch into space of the XMM X-ray telescope. It will be launched on the fourth flight of the Ariane 5 launcher from Kourou in French Guiana.