TITLE:   GCN GRB OBSERVATION REPORT
NUMBER:  1652
SUBJECT: GRB021004: Optical Observations
DATE:    02/10/24 06:39:12 GMT
FROM:    Grant Williams at Steward Observatory  <gwilliams@as.arizona.edu>

G. Williams (MMTO/SAO), K. Lindsay (Clemson University), P.  Milne (LANL)

We observed the optical afterglow of GRB021004 (Fox et al., GCN 1564) with
the Steward Observatory 90-inch Bok Telescope.  We obtained 8 x 300s
exposures in each of the B, V, R, and I bands.  Observations began at
04:19:49 UT, and ended at 07:39:15 UT, on 12 October 2002 (T + 7.67 - 7.82
days).  Aperture photometry was performed on the coadded images and the
results were calibrated utilizing standards reported by Henden et al., GCN
1583.  The following preliminary results were obtained:

B = 22.60 +- 0.11  (12 Oct 07:18 UT)

V = 21.95 +- 0.07  (12 Oct 06:23 UT)
 
R = 21.47 +- 0.09  (12 Oct 04:41 UT)

I = 21.23 +- 0.18  (12 Oct 05:31 UT)

This report may be cited.