TITLE:   GCN CIRCULAR
NUMBER:  23244
SUBJECT: GRB 180914B : TSHAO optical observations
DATE:    18/09/17 10:26:49 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Pozanenko (IKI), I. Reva (FAPHI), A. Kusakin 
(FAPHI), A. Volnova (IKI), M. Krugov (FAPHI) report on behalf of larger 
GRB follow-up collaboration:

We observed the field of GRB 180914B (Ursi, et al., GCN  23226; Bissaldi 
et al., GCN 23232;  Frederiks et al., GCN 23240) with Zeiss-1000 1-m 
telescope of Tien Shan Astronomical Observatory starting on September 16 
(UT) 19:44:34, obtaining a total of 46.5 minutes exposure in the 
Rc-band. Within XRT position (D'Ai et al., GCN 23236)  we detect the 
object reported by Zheng & Filippenko (GCN 23237), Troja et al. (GCN 
23238),  (Paul & Kuin, GCN 23241). Preliminary photometry of the objext 
is following.

Date       UT start t-T0    Filter Exp.  OT    Err. UL
                     (mid, days) (s)

2018-09-16 19:44:34 2.07692 R      31*90 19.89 0.05 21.9

The photometry is based on several nearby SDSS-DR9 stars.
SDSS-DR9_id            R(Lupton)
J220926.80+250130.1    15.705
J220922.87+250206.0    16.156
J220929.88+250257.7    15.812
J220928.05+250309.0    17.230
J220928.90+250327.6    15.524
J220924.12+250415.7    15.485
J220920.37+250610.6    15.050
J220902.04+250312.5    15.321




-- 
Лена Мазаева