TITLE:   GCN CIRCULAR
NUMBER:  29032
SUBJECT: GRB 201203A: Zeiss-1000 (Koshka observatory) optical upper limit
DATE:    20/12/12 22:21:35 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

N. Pankov (HSE),  A. Zhornichenko (KIAM),   A. Pozanenko (IKI),  A. 
Novichonok (Petrozavodsk State University, KIAM), S. Belkin (IKI), 
report  on behalf of IKI GRB FuN:

We observed the field of  GRB 201203A (Dichiara  et al., GCN 28985) with 
Zeiss-1000 telescope of Koshka observatory starting on Dec. 03 (UT) 
20:50:46. We do not detect any optical source within XRT position 
(D'Elia  et al., GCN 28990) in agreement with previous observations 
(Jelinek et al., GCN 28986, Watson et al., GCN 28987, Zheng et al., 
28988, Niwano et al., GCN 28992, Kumar et al. GCN 28993; Kumar et al. 
GCN29030)

Preliminary photometry of the field is following

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

2020-12-03 20:50:46   0.58216    R      120*25   n/d  n/d   20.5


The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
USNO_B10_0634-0041449
USNO_B10_0634-0041608
USNO_B10_0634-0041460
USNO_B10_0635-0033957