Chandra X-ray Observatory
Within four hours of the burst's detection, observations made by BATSE and the Rossi X-ray Timing Explorer were able to determine the burst's position of α = 77.38 ± 0.04, δ = 11.30 ± 0.05. This rapid determination allowed astronomers to conduct follow-up studies using optical and X-ray telescopes. Other instruments which detected GRB 991216 included the Chandra X-ray Observatory, the MDM Observatory, and the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope. This was the first use of the Chandra X-ray Observatory for the purpose of gamma-ray burst detection.