GCN Circular 1916
A. Henden (USRA/USNO) reports on behalf of the USNO GRB team: We have acquired BVRcIc all-sky photometry for a 20x20 arcmin field centered at the coordinates for the optical transient (Fox et al., GCN 1879) associated with the HETE burst GRB030226 (Suzuki et al., GCN 1888) 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/grb030226.dat The astrometry in this file is based on linear plate solutions with respect to UCAC2. The external errors are less than 100mas. The estimated external photometric error is 0.03mag. In particular, the two comparison stars listed by Garnavich, et al. (GCN 1885) can be found in this file with Rc magnitudes: ID Garnavich Henden Star A 15.39 15.45 Star B 17.06 17.05 In agreement within the quoted errors. This calibration will be extended with additional nights to ensure against a systematic zeropoint error, but current weather forecasts indicate that this may be a week or two. We will not be performing U-band calibration unless requested. As always, you should check the dates on the .dat file prior to final publication to get the latest photometry.