Gamma-ray bursts (GRBs) are extremely energetic flashes of radiation detected about twice a day from somewhere in the universe. They were discovered in 1967 by US military satellites and observed systematically by NASA’s Compton Gamma Ray Observatory from 1991 onwards. But it was not until the launch of the Italian/Dutch BeppoSAX satellite in 1996 that scientists were able to accurately locate GRBs.

In 1997, researchers working on the BeppoSAX project discovered that GRBs emit X-rays for several days, and astronomers at the University of Amsterdam confirmed that the bursts also emit at optical wavelengths. These observations led to the discovery that GRBs originate in very distant galaxies.

Then, in 1998, astronomers at the University of Amsterdam observed a GRB that took place at the same time as a stellar explosion. It was subsequently discovered that a significant fraction of gamma-ray bursts are related to very powerful stellar explosions known as hypernovae. Exactly how such GRBs are created remains a mystery, however, and the nature of the remaining bursts is unknown.

Lars Fugger of Aarhus University Hospital in Copenhagen and co-workers in Denmark, Sweden, the UK and the US shared the prize for their work on the immunological basis of multiple sclerosis. The winners were selected from a short list of ten by a panel of eminent academics and industrialists. Altogether there were 108 entries for the prize, which recognizes outstanding research made possible by European collaboration.