[vsnet-grb-info 2770] GRB060124, BVRcIc field calibration

[GCN Circulars]

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  <arne at aavso.org>

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.