Supernova fireball. Coloured Hubble Space Tele- scope image of the supernova fireball (white blob) which accompanied a gamma ray burst (GRB). This is the first-ever optical image to link a GRB with a host galaxy (E"-shaped object to the lower right of the GRB). GRBs are very powerful bursts of gamma radiation that flare and then disappear in a few seconds; the fireball here remained visible for a number of days. The GRB occurred outside the galaxy's core, suggesting that it was caused by a collision between either two neutron stars or a neutron star & a stellar-mass black hole. Image of GRB 970228 detected on 28 February 1997."