[vsnet-grb-info 21779] GRB 190203A: Mondy optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  23878
SUBJECT: GRB 190203A: Mondy optical observations
DATE:    19/02/06 18:09:10 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen at iki.rssi.ru>

A. Volnova (IKI),  E. Klunko (ISTP),  A. Pozanenko (IKI), E. Mazaeva 
(IKI), S. Belkin (IKI)  report   on behalf of IKI-GRB-FuN:

We observed the field of  GRB 190203A  (Lien et al.  GCN 23845) with 
AZT-33IK telescope of Sayan observatory (Mondy) starting on Feb. 03 (UT) 
  16:23:21.   We   detected  the optical afterglow (Lien et al. GCN 
23845; Moskvitin  et al., GCN 23847; Lipunov et al. GCN 23850). 
Preliminary photometry of the afterglow is following.

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

2019-02-03 16:23:21   0.04807    R      30*120  21.14  0.27   21.3

The photometry is based on the nearby USNO-B1 stars used in GCN 23847.