On January 23, 1999, a gamma-ray burst was detected by the BATSE and Beppo-SAX satellites. The location of this event was received on the ground 4 seconds after the burst began. The Robotic Optical Transient Search Experiment (ROTSE) began observations of the burst location 22 seconds after it started, and detected a violently variable, extremely bright transient object. At its brightest this object was millions of times as bright as a supernova. I will describe the ROTSE instrumentation, outline the remarkable international collaboration which made this detection possible, and describe the implications of this discovery for our understanding of these most violent of astrophysical explosions.

ROTSE is a collaboration between the University of Michigan, Los Alamos National Lab, and Lawrence Livermore National Lab.