TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1917
SUBJECT: GRB030227, BVRcIc field photometry
DATE:    03/03/03 18:20:20 GMT
FROM:    Arne A. Henden at USNO/USRA  <aah@nofs.navy.mil>

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 (Castro-Tirado et al., GCN 1904)
associated with the INTEGRAL burst GRB030227 (Gotz et al.,
GCN 1895, 1896) 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/grb030227.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.

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.