TITLE:   GCN CIRCULAR
NUMBER:  28333
SUBJECT: GRB 200829A: Koshka Zeiss-1000 optical observations
DATE:    20/08/31 19:52:13 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

A. Volnova (IKI), S. Naroenkov (INASAN),  A. Pozanenko (IKI), N. Pankov 
(HSE), S. Belkin (IKI), E. Mazaeva (IKI)  report on behalf of larger GRB 
IKI FuN collaboration:

We observed the the field of GRB 200829A (Siegel et al., GCN 28307; Ursi 
et al., GCN 28314; Ridnaia et al., GCN 28323; Lesage & Meegan, GCN 
28326)  with Zeiss-1000 1-m telescope of Koshka Observatory on August, 
30  starting (UT) 19:18:21 in I- and R-filters. The optical afterglow 
(Siegel et al., GCN 28307, Pozanenko et al., GCN 28308; Kuin & Siegel, 
GCN 28311; Lipunov et al., GCN 28315; Vinko et al., GCN 28316; Hentunen 
et al., GCN 28318; Moskvitin et al., GCNs 28322, 28328, Zhu et al., GCN 
28324, GCN 28330; Pankov et al., GCN 28329; Izzo, GCN 28331)  is 
detected  in stacked images of both filters. Preliminary photometry of 
the afterglow is following.

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

2020-08-30 19:18:21   1.29067    I     47*120  20.14  0.20  20.8
2020-08-30 19:20:31   1.29217    R     47*120  21.0   0.25  21.4


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