Detection of GRB 970228

Date: February 28, 1997 • Location: Rome, Italy

GRB 970228, a highly luminous 80-second flash of gamma rays, was detected on Earth, providing early evidence that gamma-ray bursts occur well beyond the Milky Way.

GRB 970228 was the first gamma-ray burst (GRB) for which an afterglow was observed. It was detected on 28 February 1997 at 02:58 UTC. Since 1993, physicists had predicted GRBs to be followed by a lower-energy afterglow, but until this event, GRBs had only been observed in highly luminous bursts of high-energy gamma rays ; this resulted in large positional uncertainties which left their nature very unclear.