GCN Circular 1971
Subject
GRB030131, BVRcIc field photometry
Date
2003-03-27T20:22:19Z (21 years ago)
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 candidate
afterglow coordinates (Fox et al., GCN 1857)
for the INTEGRAL burst GRB030131 (GCNs 1836, 1838, 1847)
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/grb030131.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 star located at RA(J2000)=13:28:18.16
DEC(J2000)=30:38:20.79, used as a comparison star by
Gorosabel et al. (GCN 1866) has B=18.95 +/- 0.03, making
the OT fainter than what was given in that GCN.
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.