[vsnet-grb-info 23919] GRB 191016A: AZT-20 (Assy observatory) optical photometry

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  26018
SUBJECT: GRB 191016A: AZT-20 (Assy observatory) optical photometry
DATE:    19/10/17 10:18:43 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

V. Kim (AFIF, Pulkovo Observatory) A. Pozanenko (IKI), M. Krugov (AFIF), 
  I. Reva (AFIF), E. Mazaeva  (IKI), A. Volnova (IKI) report on behalf 
of larger GRB IKI FuN collaboration:

We observed the field of the  GRB 191016A   (Gropp al., GCN  26008) with 
AZT-20 telescope  of Assy-Turgen observatory (MPC observatory code 217) 
starting on Oct. 16  (UT) 14:58:49  in  r'-filter.    We clearly detect 
the optical afterglow (Watson al., GCN  26010; Zheng al., GCN  26011; 
Watson  al., GCN  26015; Hu et al., GCN 26017).
Preliminary photometry of the afterglow is following.

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

2019-10-16 14:58:49   0.48336     r'    120*30 20.6 0.15

The photometry is based on the nearby USNO-B1  stars and BRI 
transformations to r'.

The photometry in agreement with non detection of the optical afterglow 
by Jelinek et al. (GRB 26013).