TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4607 SUBJECT: GRB060124, BVRcIc field calibration DATE: 06/01/27 17:17:17 GMT FROM: Arne A. Henden at AAVSO A. Henden (AAVSO/USNO) reports on behalf of the USNO GRB Team: We have acquired BVRcIc all-sky photometry for an 11x11 arcmin field centered on the coordinates of the optical afterglow (Kann et al., GCN 4577) for the Swift burst GRB060124 (Holland et al., GCN 4570) with the USNOFS 1.0-m telescope on one photometric night. Stars brighter than V=13.5 are saturated and should be used with care. We have placed the photometric data on our anonymous ftp site: ftp://ftp.nofs.navy.mil/pub/outgoing/aah/grb/grb060124.dat The astrometry in this file is based on linear plate solutions with respect to USNO-A2. The external errors are about 300mas. The estimated external photometric error is about 0.02mag. As always, you should check the dates on the .dat file prior to final publication to get the latest photometry. There is a README file on the ftp directory to give you information about the procedures used to calibrate these fields.