TITLE:   GCN CIRCULAR
NUMBER:  29191
SUBJECT: GRB 201020B: Assy, Koshka, Mondy and Maidanak optical observations
DATE:    20/12/28 21:53:13 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI),  A. Pozanenko (IKI), V. Kim (FAI, Pulkovo Observatory), 
   M. Krugov (FAI), A. Novichonok (Petrozavodsk State University, KIAM), 
A. Zhornichenko (KIAM),  E. Klunko (ISTP),   O. Burhonov (UBAI), Sh. 
Ehgamberdiev (UBAI) report  on behalf of IKI GRB FuN:

We additionally observed the GRB 201020B (Fermi GBM team, GCN 28702; 
Malacaria et al., GCN 28710; Arimoto et al., GCN 28716; Ursi et al., GCN 
28714; Ridnaia et al., GCN 28723) with AZT-20 telescope of Assy 
observatory, Zeiss-1000 of Koshka observatory, AZT-33IK telescope of 
Sayan observatory (Mondy), and AZT-22 telescope of Maidanak observatory. 
The optical afterglow (Lipunov et al., GCN 28718; Xu et al., GCN 28719; 
Belkin et al., GCN 28725; Breeveld & Lien, GCN 28743; Vinko et al., GCN 
28750; Kumar et al., GCN 28753; Belkin et al., GCN 28768; Vinko et al., 
GCN 28769; Vinko et al., GCN 28769; Panchal et al., GCN 28772; Nicastro 
  et al., GCN 28773; Kumar  et al., GCN 28776; Kumar  et al., GCN 28781) 
with redshift of z= 0.804 (Kann  et al., GCN 28765) is  detected in most 
of stacked images of our observations in R-filter.

Preliminary light curve of the afterglow based on our observations 
including reported earlier (Belkin et al., GCNs 28725, 28768) can be 
found in

http://grb.rssi.ru/GRB201020B/GRB201020B_R_LC.png

The photometry is based on the nearby USNO-B1.0 stars
USNO-B1.0_id R2
1670-0037414 16.74
1670-0037586 16.16