The optical afterglow of gamma-ray burst GRB-990123 was imaged on January 23, 1999.
Astronomers obtained a visible-light image of GRB 990123 as it occurred on January 23, 1999, using the ROTSE-I telescope, sited in Los Alamos, New Mexico. The robotic telescope was fully automated, responding to signals from NASA's BATSE instrument aboard the Compton Gamma Ray Observatory within seconds, without human intervention. This was the first GRB for which optical emission was detected before the gamma-ray emission had ceased. Read more