GCN Circular 4687
P.R. Wozniak, W.T. Vestrand, J. Wren, R. White, and S. Evans at Los Alamos National Laboratory on behalf of the RAPTOR team report: RAPTOR's autonomous system for locating optical counterparts to GRBs identified a variable object at position RA=202.931, DEC=35.0509 deg. At 2900 seconds after the trigger RAPTOR measured an R-band magnitude of ~17.3, followed by a brightening to ~16.3 mag over the next 700 seconds, where it remained for about 200 seconds before fading to ~16.9 mag over the next 45 min. The real time position was reported only to the RAPTOR rapid response team because of unusual photometric behavior of the object. This variable source has a location consistent with the position of the optical afterglow candidate found by Fynbo et al. (GCN 4683) and confirmed by Boyd et al. (GCN 4684).