TITLE:   GCN CIRCULAR
NUMBER:  29198
SUBJECT: GRB 201104B: Maidanak and CrAO optical observations
DATE:    20/12/29 22:49:38 GMT
FROM:    Alexei Pozanenko at IKI, Moscow  <apozanen@iki.rssi.ru>

S. Belkin (IKI), A. Pozanenko (IKI), V. Rumyantsev (CrAO),  O. Burhonov 
(UBAI), Sh. Ehgamberdiev (UBAI) report  on behalf of IKI GRB FuN:

We observed GRB 201104B (Sbarufatti et al., GCN 28825) with AZT-22 
telescope of Maidanak Observatory  and ZTSh telescope of CrAO.
The optical afterglow (Marshall et al., GCN 28827; Vielfaure  et al., 
GCN 28840; Oates  et al., GCN 28851; Belkin et al., GCNs 28852, 28856, 
28871; Gupta et al., GCN 28860; Hosokawa et al., GCN 28870) at redshift 
z = 1.954 (Vielfaure et al., GCN 28840) is detected in stacked images. 
Preliminary photometry of the afterglow is following.

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

2020-11-09 15:57:43  4.95413 R 12*300 22.89 0.09 24.3 AZT-22
2020-11-13 19:50:05  9.12784 R 45*120 23.20 0.12 24.0 ZTSh

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

A light curve base on our observations including reported earlier 
(Belkin et al., GCNs 28852, 28856, 28871) can be found in

http://grb.rssi.ru/GRB201104B/GRB201104B_LC_R.png