Gamma-ray bursts are the most powerful explosions ever detected in the Universe. They are also one of the greatest mysteries of modern astronomy, since so far no clear evidence has existed to prove what causes them.

Until now, there have been two 'prime suspects' for what makes gamma-ray bursts, the collision of neutron stars - dead, ultra-dense stars - or the death of very massive stars in supernova explosions. The new results from the XMM-Newton X-ray space telescope rule out the first hypothesis and confirm the second, at least for the gamma-ray burst that occurred on December 11, 2001. reports ESA

However, not all supernovas have produced gamma-ray bursts, and the mechanism of how the burst is actually created is still unknown