English: The Optical Transient of Gamma Ray Burst 011121 The blue dot in the center of this image (shown by the arrow) is the optical light signature of Gamma Ray Burst 011121. The gamma ray burst briefly appeared brighter than the rest of the Universe in gamma rays, before rapidly fading away. The burst was also detected in X-rays by the BeppoSAX satellite, which provided the burst's position in the sky with sufficient accuracy for ground-based telescopes to detect and image the gamma ray burst in the ultraviolet, optical, infrared and radio. This optical image, taken with the National Science Foundation's Blanco 4-meter telescope at Cerro Tololo Inter-American Observatory in Chile during the morning of 23 November 2001, shows the optical transient a day and a half after the initial burst. The transient had faded in brightness from its peak by more than a factor of 100 in that period of time. The reddish dot adjoining the gamma ray burst, at its lower left, is probably the core of the galaxy in which the gamma ray burst occurred. For further information about NOAO's efforts to follow-up these incredibly energetic extragalactic explosions, see https://www.noao.edu/noao/grb