that the burst occurred in a binary system where a neutron star orbited a normal helium star that had just entered its red giant phase, which had enormously expanded its outer atmosphere. During the expansion, the red giant star engulfed the neutron star, resulting in both the ejection of the giant's atmosphere and rapid tightening of the neutron star's orbit. Once the two stars became wrapped in a common envelope of gas, the neutron star may have merged with the giant's core after just five orbits, or about 18 months. The end result of the merger was the birth of a black hole or a magnetar and the production of oppositely directed jets of particles moving at nearly the speed of light, followed by a weak supernova. The particle jets produced gamma rays. Jet interactions with gas ejected before the merger explain much of the burst's different nature. Based on this interpretation, the event took place about 5.5 billion light-years away (redshift 0.33), and the team has detected what may be a faint galaxy at the right location. An alternative hypothesis, offered by a team led by Sergio Campana of the Brera Astronomical Observatory (INAF), proposes that GRB 101225A was produced by a comet-like object that fell into a neutron star located in our own galaxy, only some 10,000 light-years from Earth. In this model, the comet-like object falls onto the neutron star and is disrupted by tidal forces. Hard X-ray emission (the burst) results from the first matter falling onto the neutron star. X-ray emission and initial variations detected by Swift are attributed to clumps of material striking the star as the disc formed around it. Then the disk cools down and emits only at UV and optical wavelengths. More recently, at the 2013 Huntsville Gamma-ray Burst Symposium, several scientists proposed that GRB 101225A, along with GRB 111209A and 121027A are part of a new class of gamma ray bursts, termed ultra-long bursts and caused by the collapse of low metallicity blue supergiant stars. Andrew Levan and his colleagues used the Gemini North Telescope to determine that GRB 101225A was 7 billion light years distant much further than original estimates. This greater distance gives it a much higher energy level, which combined with longer duration and an absence of a supernova signature have led scientists, such as Bruce Gendre to suggest that these ultra-long bursts are the result of