TITLE:   GCN CIRCULAR
NUMBER:  16814
SUBJECT: GRB 140907A: Mondy optical observations
DATE:    14/09/11 16:53:02 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), E. Klunko (ISTP), M. Eselevich (ISTP), I. Korobtsev 
(ISTP), A. Pozanenko (IKI) report on behalf of larger GRB follow-up 
collaboration:

We observed the field of the Swift GRB 140907A  (Krimm et al., GCN 
16788) with with AZT-33IK telescope of Sayan observatory (Mondy). We 
obtained several images on Sep., 08 and Sep. 9.  Within enhanced XRT 
error circle  (Goadet al., GCN 16795) we clearly detect the afterglow 
(Xu et al., GCN 16789; Kuin and Krimm, GCN 16791).
Preliminary photometry is following:

date        UT start  t-T0        Filter  Exp.    OT      OT_err
                       (mid, days)          (s)

2014-09-08  15:38:52  1.00888     R       82*60   21.26   0.08
2014-09-09  14:35:11  1.97786     R      120*60   22.50   0.20

The photometry is based on the same USNO-B1.0  stars which were used in 
GCN 16809:

ID           RA           Dec         R2
1366-0072961 03:12:42.62  +46:36:01.4 15.84
1365-0072251 03:12:34.50  +46:35:42.0 14.55
1365-0072223 03:12:30.14  +46:35:37.7 15.57

The light curve can be found in
http://grb.rssi.ru/GRB140907A/GRB14907A_lc1.png