TITLE: GCN GRB OBSERVATION REPORT NUMBER: 664 SUBJECT: GRB000424, UBVRI field photometry DATE: 00/05/03 23:31:21 GMT FROM: Arne A. Henden at USNO/USRA A. Henden (USRA/USNO) reports on behalf of the USNO GRB team: We have acquired preliminary UBVRcIc all-sky photometry for an 11x11 arcmin field that covers the error box for GRB000424 with the USNOFS 1.0-m telescope on one marginally photometric night. Stars brighter than V=14 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/grb000424.dat The current photometry has a potential external zero-point error of about three percent. The astrometry in this file is based on linear plate solutions with respect to USNO-A2.0. The internal errors are less than 100mas. Further calibration of this field will be performed if an optical afterglow is identified.