TITLE: GCN CIRCULAR NUMBER: 28359 SUBJECT: GRB 200829A: optical observations, a light curve in R-filter DATE: 20/09/03 15:15:47 GMT FROM: Alexei Pozanenko at IKI, Moscow A. Pozanenko (IKI), N. Pankov (HSE), S. Belkin (IKI), A. Volnova (IKI), I. Reva (FAPHI), A. Zhornichenko (KIAM), A. Novichonok (Petrozavodsk State University, KIAM), S. Naroenkov (INASAN), K. Antoniuk (CrAO), R.Ya. Inasaridze (AbAO), E. Mazaeva (IKI), Sh. Ehgamberdiev (UBAI) 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 telescope of TShAO observatory, RC-36 telescope of Kitab observatory, Zeiss-1000 telescope of Koshka Observatory, AZT-11 telescope of CrAO observatory, and AS-23 telescope of AbAO observatory. 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., GCNs 28324, 28330; Pankov et al., GCN 28329; Izzo, GCN 28331; Volnova et al., GCN 28333) is detected on first two days after GRB trigger. Preliminary light curve of the afterglow in R-filter can be found at http://grb.rssi.ru/GRB200829A/GRB200829A_LC1_R.png One can tentatively assume a jet break in the light curve at ~0.33 days. (The photometry is based on nearby USNO-B1.0 stars identical for all observations.)