[vsnet-grb-info 20005] GRB 171102B: TShAO optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  22092
SUBJECT: GRB 171102B: TShAO optical upper limit
DATE:    17/11/03 20:49:21 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

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

We observed the field of the Swift  GRB 170822A   (Ukwatta et al.,
GCN  22082) with Zeiss-1000 1-m telescope of Tien Shan Astronomical 
Observatory starting on Nov., 02 (UT) 15:47:45.  We took several images 
in R-filter.  Within enhanced XRT error circle  (Osborne et al., GCN 
22084) we do not detect  any  object.  Preliminary  photometry of the 
afterglow is following.

Date       UT start   t-T0    Filter Exp.  OT     Err. UL
                      (mid, days)     (s)             (3 sigma)


2017-11-02 15:47:45  0.04377  R    30*120  n/d    n/d  20.1


Photometry is based on nearby USNO-B1.0 stars R2 magnitudes
USNO-B.1_id  R2
1124-0422739 16.70
1124-0422527 16.20
1124-0422440 15.76