Follow-up observations of the burst's afterglow by the Hubble Space Telescope and ground-based observatories were unable to determine the object's distance using spectroscopic methods.
[4] On January 6, 2011, the 10m Keck-I telescope equipped with the Low Resolution Imaging Spectrometer (LRIS) conducted spectroscopic measurements of the host galaxy of GRB 101225A.
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.
[1][8] 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.
X-ray emission and initial variations detected by Swift are attributed to clumps of material striking the star as the disc formed around it.
Andrew Levan and his colleagues used the Gemini North Telescope to determine that GRB 101225A was 7 billion light years distant[10][11][12] 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 collapsing blue supergiant stars.