TITLE:   GCN CIRCULAR
NUMBER:  19498
SUBJECT: GRB 160601A: AbAO optical observations
DATE:    16/06/03 18:19:24 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

E. Mazaeva (IKI), A. Volnova  (IKI), R. Inasaridze (AbAO), V. Ayvazian 
(AbAO), I. Molotov (KIAM), A. Pozanenko (IKI) report on behalf of larger
GRB follow-up collaboration:

We observed the field of of the Swift  GRB 160601A (Kocevski et al., GCN 
19478) with AS-32 (0.7m) telescope of Abastumani Observatory starting on 
June, 01 (UT) 19:07:28. We obtained several unfiltered images of the 
field. In a combined image we detected both NOT sources (Malesani et 
al., GCN 19485). Preliminary photometry  of the optical afterglow (NOT 
source #1,  Schulze et al., GCN 19488) are following

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

2016-06-01  19:07:28   0.20169 CR     26*120  22.9+/-0.3 23.0


Photometry is based on nearby SDSS-DR9 stars, Lupton transformations 
into R:
SDSS-DR9_id            R(Lupton)
J153959.67+643325.7    16.72
J153956.37+643102.2    17.00
J153931.88+643247.0    17.02
J153927.50+643304.3    19.23
J153942.70+643016.4    16.27
J153948.64+643150.1    19.27
J153948.72+643220.0    19.86