TITLE:   GCN CIRCULAR
NUMBER:  18920
SUBJECT: GRB 160121A: TSHAO optical afterglow confirmation
DATE:    16/01/22 00:36:48 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the Swift GRB 160121A (Hagen  et al., GCN 18912) 
with Zeiss-1000 (East) 1-m telescope of Tien Shan Astronomical Observatory 
starting on Jan. 21 (UT) 16:04:44.  We obtained several images in R filter. 
We detect afterglow  (Oates et al., GCN 18917) in a combined image within 
center of the enhanced Swift-XRT position (Osborne et al., GCN 18918). 
Preliminary photometry of the afterglow is following

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

2016-01-21 16:04:44    0.12598  R       29*180  20.26  0.22


The photometry is based on nearby USNO-B1.0 stars.

USNO-B1.0_id    R2
0664-0122909    16.87
0664-0122918    16.73
0664-0122943    17.72
0664-0123015    18.03
0663-0123485    16.91