[vsnet-grb-info 7046] GRB 081128: optical observation in CrAO

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  8630
SUBJECT: GRB 081128: optical observation in CrAO
DATE:    08/12/06 15:33:01 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

V. Rumyantsev, D. Shakhovkoy, S. Sergeev (CrAO), M.Andreev (Terskol Branch 
of Institute of Astronomy), A. Pozanenko (IKI) on behalf of larger GRB 
follow up collaboration report:

We observed the error box of Swift GRB 081128 (Margutti  et al, GCN 8571) in 
R band on Nov. 28 between (UT) 17:53:23 - 19:05:55 with AZT-11 telescope of 
CrAO. Inside the refined XRT error box (Evans et al. GCN 8573) we detect the 
source reported as possible afterglow (Wang et al, GCN 8572; Lin et al, GCN 
8575; Andreev et al, GCN 8576; Guidorzi et al, GCN 8577).  The coordinates 
of the source are   RA(J2000):  01 23 13.03 Dec(J2000): +38 07 37.7 with 
uncertainty of 0.5". A photometry based on  USNO-B1.0 star 1281-0027628 
(01:23:11.75 +38:07:43.6) R2=17.91 is following:

T0+    Filter,  Exp.,   mag.        UL
(h)             (s)                (3 sigma)

1.207  R        23x180  21.5 +/-0.2  22.4

Taking above photometry and photometry reported earlier  (Lin et al, GCN 
8575; Andreev et al, GCN 8576; Guidorzi et al, GCN 8577) we confirm the 
fading nature of the source. We also detected the source  (Guidorzi et al, 
GCN 8577) which is ~4"  South of OT.

A combined image can be found at 
http://grb.rssi.ru/GRB081128/GRB081128_AZT11_R_18_31_09.gif