The team were able to obtain an ultra violet spectrum of the early stages of a gamma ray burst (GRB) just 251 seconds after its onset - the earliest ever captured. It is currently thought that some GRBs are caused by immense explosions following the collapse of the core of a rapidly rotating, high-mass star into a black hole, but there are still many mysteries surrounding them.

Paul Kuin, from the Mullard Space Science Laboratory (MSSL) at UCL, said: “By looking at these earlier moments of gamma ray bursts, we will not only be able to better calculate things such as the luminosity and distance of a burst, but to find out more about the galaxies that play host to them and the impact these explosions have on their environments. Once this new technique is applied to much brighter bursts, we’ll have a wealth of new data.”

Since its launch in 2004, the Swift satellite has provided the most comprehensive study so far of GRBs and their afterglows. Using the Ultra Violet /Optical Telescope to obtain ultraviolet spectra, the Swift team will be able to build on this study and even determine more about the host galaxies’ chemistry.
Paul Kuin from MSSL said: “The new spectrum has not only allowed us to determine the distance of the gamma ray burst’s host galaxy but has revealed the density of its hydrogen clouds.  Learning more about these far-away galaxies helps us to understand how they formed during the early universe. The gamma ray burst observed on this occasion originated in a galaxy 8 billion light years from Earth.”