Gamma-ray Burster . ... Explanation: Gamma-ray bursts seem to be the most powerful explosions in the Universe. ... These Apache Point Observatory optical images from Monday and Tuesday this week have helped identify a faint, fading object (red arrow) near the position of a gamma-ray burst . ... Though thousands of bursts have been detected by satellites sensitive to gamma rays, it is likely that this object represents only the third known optical counterpart to a gamma-ray burst . ...