[vsnet-grb-info 21747] GRB 190203A: Koshka Zeiss-1000 optical upper limit

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23846
SUBJECT: GRB 190203A: Koshka Zeiss-1000 optical upper limit
DATE:    19/02/03 16:51:04 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Novichonok (KIAM), A. Pozanenko (IKI), E. Mazaeva (IKI),  S. Belkin 
(IKI), A. Volnova (IKI),  I. Molotov (KIAM) report on behalf of larger 
GRB follow-up collaboration:

We observed the field of GRB 190203A (Lien , et al., GCN  23845)   with 
Zeiss-1000 1-m telescope of Koshka Observatory starting on Feb. 03  (UT) 
02:40:34 in  R-filter under not optimal weather conditions.   We do not 
detect the optical afterglow candidate (Lien , et al., GCN  23830). 
Preliminary photometry of the combined of first 4 images of 4*180 
seconds started on 2019-02-03 16:01:10 is R=19.5. Observation is continuing.

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