[vsnet-grb-info 23763] GRB 190926A: AbAO upper optical limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  25862
SUBJECT: GRB 190926A: AbAO upper optical limit
DATE:    19/09/29 10:55:59 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI), R. Ya. Inasaridze (AbAO, 
Samtskhe-Javakheti State University), E. Mazaeva (IKI), A. Volnova 
(IKI),  V. R. Ayvazian  (AbAO, Samtskhe-Javakheti State University), 
G.V.  Kapanadze (AbAO, Samtskhe-Javakheti State University), I. Molotov 
(KIAM) report on behalf of larger IKI GRB follow-up collaboration:

We observed  GRB 190926A (Melandri et al., GCN 25848) with AS-32 (0.7m) 
telescope of Abastumani Observatory starting on Sep. 27 (UT) 01:16:46. 
We obtained several 60 s exposures  in R-filter. We do not detect any 
source within enhanced Swift-XRT position (Goad et al., GCN 25850) in 
the stacked image. Photometry of the field  is following

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

2019-09-27 01:16:46 0.6493   R    21*60  n/d   n/d  20.8

Photometry is based on nearby USNO-B1.0 star (R2 magnitude):

USNO-B1.0_id R2
1496-0169403 18.52


The non detection in an agreement with previously reported results 
(Lipunov et al., GCN #25849, Zheng & Filippenko, GCN # 25852, Oates & 
Melandri, GCN #25853, Adachi et al., GCN #25854; Kann et al., GCN #25856).