TITLE:   GCN CIRCULAR
NUMBER:  8175
SUBJECT: GRB 080903: optical observations
DATE:    08/09/03 12:39:23 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

Andreev M., Sergeev A., Karpov N. (Terskol Branch of Institute of
Astronomy),  Khramtsova M. (The Ural State University),  Petkov V.(BNO INR
RAS), A. Pozanenko (IKI) on behalf of larger GRB follow up collaboration
report:

We observed the field of GRB 080903 (Grupe et al. GCN 8169)  with Z-600 and
Celestron 11" telescopes of Mt. Terskol observatory.  A set of  60 s
exposures in R filter was taken with Z-600 starting 22 minutes after burst
onset. In a combined image we clearly detect afterglow candidate (Ugarte
Postigo et al. GCN 8172, Korotkiy et al. GCN 8173). Preliminary photometry
is based on USNO-A2.0 1350-06155883 star (05 47 16.36 +51 15 56.4) assuming
R=18.1:

T0+       Exp.        R_mag
(Mid)

1673 sec. 10x60 sec.  19.35 +/-0.2

The afterglow is also detected in unfiltered combined image (40x10s) taken
with Celestron 11" telescope at Tmid = 1280 s. The photometry is underway.