TITLE:   GCN CIRCULAR
NUMBER:  19825
SUBJECT: GRB 160816A: ISON/UAFO optical observations
DATE:    16/08/19 15:34:50 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI),  E. Chornaya (UAFO, ISON), A. Matkin (UAFO), I. 
Molotov (KIAM), A. Pozanenko (IKI) report on behalf of  larger GRB 
follow-up collaboration:

We observed the field of GRB 160816A  (Racusin et al., GCN 19802; 
Mailyan et al., GCN 19804)   with SANTEL-650 (0.65m)  telescope  of 
UAFO/ISON-Ussuriysk observatory. We obtained several unfiltered images 
starting on  August 17 (UT) 11:47:34.  We detected  optical afterglow 
(Guidorzi et al. GCN 19808; Troja et al. GCN 19809). Preliminary 
photometry of a combined image is following

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

2016-08-17 11:47:34 0.80873  CR      275*20 20.90  0.22  21.5

Photometry is based on nearby USNO-B1.0 stars
USNO-B1.0_id    R2
1271-0576219    17.27
1271-0576200    17.52
1271-0576190    18.12
1271-0576101    17.00
1271-0576308    17.05