[vsnet-grb-info 12458] GRB 121001A: possible optical counterpart

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13833
SUBJECT: GRB 121001A: possible optical counterpart
DATE:    12/10/01 20:32:27 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

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

We observed field of the Swift  GRB 121001A = Swift trigger 535026 (D'Elia 
et al. GCN  13831) with Zeiss-600 telescope of Mt.Terskol observatory in R 
filter starting on Oct. 01 (UT) 18:39:20.  In a stacked image of first 13x60 
exposures we detect optical source in coordinates (J2000) RA=18 24 07.8 
Dec=-05 39 55.3 which is consistent with XRT error circle (GCN  13831). The 
optical source is absent in DSS2 plates. However at that time we cannot 
determine if the source is variable. Preliminary photometry of the source 
against nearby USNO B1.0 stars is 19.5R.  Finding chart can be found at
http://grb.rssi.ru/GRB121001A/GRB121001A_R_Z600_fc_1.png