TITLE: GCN CIRCULAR NUMBER: 9643 SUBJECT: GRB 090709A: RAPTOR Limits During Gamma-Ray Emission DATE: 09/07/09 23:41:47 GMT FROM: James Wren at LANL J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman of Los Alamos National Laboratory report: The RAPTOR telescope system responded to Swift trigger 356890 (Morris et al., GCN 9625) under good observing conditions. Our narrow-field instruments began observing the location at 07:39:03.4 UTC, 28.8 s after the Swift trigger (7.1 s after receipt of GCN message). We obtained simultaneous observations during the gamma-ray emitting interval in Cousins V, R, and I bands as well as unfiltered data. We do not detect the counterpart observed by the Subaru Telescope (Aoki et al., GCN 9634) and PARITEL (Morgan et al., GCN 9635). The data from our unfiltered and filtered systems was calibrated to the USNO-B1 catalog. We can put the following limits on the prompt emission: t-mid(s) exp(s) filter mag mag-err [since trigger] ---------------------------------------------------- 31.34 5 clear 17.1 5 sigma limit 52.35 5 V 14.8 5 sigma limit 52.35 5 R 15.1 5 sigma limit 52.35 5 I 15.5 5 sigma limit 89.95 40 V 16.9 5 sigma limit