TITLE:   GCN CIRCULAR
NUMBER:  28266
SUBJECT: GRB 200819A: Kitab, TSHAO optical upper limit
DATE:    20/08/19 21:04:51 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

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

We observed the field of GRB 200819A (Dichiara  et al., GCN 28263) with 
Zeiss-1000 telescope of Tien Shan Astronomical observatory starting on 
August 19 (UT) 18:03:47 and with RC-36 of Kitab observatory on (UT) 
16:30:50.   We do not detect any optical object within enhanced XRT 
position (Evans et al., GCN 28265). Preliminary photometry of the field 
is following.

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

2020-08-19  16:30:50 0.05345   CR     3600  n/d  n/d    20.0 RC-36
2020-08-19  18:03:47 0.10289   R      990   n/d  n/d    21.2 Zeiss-1000


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

Ref.stars
USNO-B1.0_id R2
1530-0056474 15.45
1530-0056771 15.06