An unusual double-end gamma ray explosion has left scientists stumped.

The gamma ray explosion, which was spotted on Christmas day 2010, was caused either by a novel type of supernova located billions of light-years away or an unusual collision within our own galaxy.

"What the Christmas burst seems to be telling us is that the family of gamma-ray bursts is more diverse than we fully appreciate," said Christina Thoene, the supernova study's lead author, at the Institute of Astrophysics of Andalusia in Granada, Spain.

Thoene's team think that the strange burst occurred in an "exotic binary system". A neutron star orbited a normal star that had just entered its red giant phase, enormously expanding its outer atmosphere. This red giant then absorbed the neutron star.

The end result of the two stars joining was a black hole and the jets of particles, or gamma ray bursts, moving in two different directions at nearly the speed of light.