TITLE:   GCN CIRCULAR
NUMBER:  23654
SUBJECT: GRB 190109B: Mondy optical upper limit
DATE:    19/01/09 15:29:40 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of the GRB 190109B (Sbarufatti et al., GCN 23648) 
with AZT-33IK telescope of Sayan observatory (Mondy).  We obtained 
several images in R-filter starting on Jan. 09 (UT) 12:17:03, i.e. 21 
minutes after the burst trigger.  We do not detect any object within 
enhanced Swift-XRT position  (Beardmore et al., GCN 23652). Preliminary 
photometry of the field is following.

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

2019-01-09  12:17:03  0.02463    R     1900   n/d     n/d   22.6

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

[GCN OPS NOTE(09jan19):  Using information from Circ# 23657, the SUBJECT-line
and first sentence has been changed from 190109A to 190109B.]