TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1025 SUBJECT: GRB010220, field photometry DATE: 01/03/28 19:12:57 GMT FROM: Arne A. Henden at USNO/USRA A. Henden (USRA/USNO) reports on behalf of the USNO GRB team: We have acquired shallow BVRcIc all-sky photometry for an 11x11 arcmin field that covers the BeppoSAX error circle for GRB010220 (GCN 956) with the USNOFS 1.0-m telescope on one marginally photometric night. Stars brighter than V=13 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/grb010220.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. Crowding will yield some unphysical stars due to astrometric and photometric blends. Further calibration of this field will not be performed this season as the field is disappearing into twilight.