TITLE: GCN CIRCULAR NUMBER: 8264 SUBJECT: GRB 080916A: Rapid PROMPT Observations DATE: 08/09/17 22:57:02 GMT FROM: Rebecca Holmes at U.North Carolina R. Holmes, M. Schubel, J. Haislip, D. Reichart, M. Nysewander, A. LaCluyze, K. Ivarsen, J. A. Crain, A. Foster, T. Brennan, and A. Trotter report: Skynet observed the localization of GRB 080916A (Ziaeepour et al., GCN 8237) with four of the 16" PROMPT telescopes at CTIO beginning 56 seconds after the trigger in UBVRI. We detect the afterglow (Fugazza et al., GCN 8238) in I. At 56 seconds after the burst we measure I ~ 17.7 mag (calibrated to 5 USNO B1 stars).