TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  391
SUBJECT: GRB 990712 Optical Observations
DATE:    99/07/19 21:04:54 GMT
FROM:    Josh Bloom at CIT  <jsb@astro.caltech.edu>

GRB 990712 Optical Observations

I. Thompson, G. W. Preston (OCIW), J. S. Bloom, F. A. Harrison, S. R.
Kulkarni, S. G. Djorgovski (Caltech), D. A. Frail (NRAO) report on behalf
of the larger GRB collaboration: "On the night of 14 July 1999 UT we
imaged the field of GRB 990712 (IAUC #7221) with the 100-inch telescope at
Las Campanas, Chile.  In a single 120-s V-band exposure we detect a faint
source coincident with the position of the optical transient discovered by
Bakos et al. (IAUC #7225). Based on the magnitudes of the 4 V-band
secondary standard stars provided by Bakos et al. (IAUC #7225), in a 3.9
arcsec radius aperture, we find V=21.88 +/- 0.24 mag (July 14.421 UT) of
the transient+host.  This magnitude is consistent with the nearly-coeval
measurement reported by Bakos et al."

This message may be cited.