GCN Circular 3535
M. Nysewander, D. Reichart, J. A. Crain, A. Foster, M. Bayliss report on behalf of the UNC team of the FUN GRB Collaboration: We observed the BAT localization of GRB 050607 (Retter et al., GCN 3525) with PROMPT beginning 13m 30s after the burst. We do not detect a source within the refined XRT localization (Pagani et al., GCN 3528) nor the source identified by Rhoads (GCN 3527). 3-sigma limiting magnitudes are based on 10 USNO-B1.0 stars for Rc and Ic observations and 10 NOMAD stars for V observations. Initial limiting magnitudes are poor due to a camera cooling error: Mean Time Integration Filter Limiting Telescope Since GRB Time Magnitude 14m 08s 1 x 77.5s Ic 17.5 PROMPT-5 17m 43s 2 x 77.5s V 18.4 PROMPT-5 21m 16m 1 x 77.5s Rc 19.7 PROMPT-5 24m 06s 1 x 77.5s Ic 19.2 PROMPT-5 26m 21s 2 x 77.5s V 19.5 PROMPT-5 29m 51s 3 x 76.25s Rc 20.5 PROMPT-5 36m 17s 4 x 76.25s Ic 20.2 PROMPT-5 41m 48s 3 x 76.25s V 19.4 PROMPT-5 47m 17s 2 x 76.25s Rc 20.3 PROMPT-5 51m 25s 1 x 76.25s Ic 19.4 PROMPT-5 Stacking all images yields 3-sigma limiting magnitudes of Ic > 20.5, Rc > 21.2, and V > 19.8. PROMPT is still being built and commissioned.