TITLE: GCN CIRCULAR NUMBER: 28000 SUBJECT: GRB 200613A: CrAO optical observations DATE: 20/06/20 11:51:17 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI),  V. Rumyantsev (CrAO),  A. Volnova (IKI), E. Mazaeva (IKI) report on behalf of larger GRB follow-up collaboration: We observed the  GRB 200613A (Fermi GBM team, GCN 27926; Bissaldi et al., GCN 27930; Ohno et al., GCN 27931; Yamaoka Ohno et al., GCN 27964)  with ZTSH 2.6m telescope of CrAO observatory starting on 2020-06-19 (UT) 18:58:23.  The optical afterglow (e.g., Kann et al., GCN 27935; Pozanenko et al., GCN 27937; Izzo et al., GCN 27939; Zhu et al., GCN 27943; Marshall, GCN 27944; Liu et al., GCN 27949; Belkin et al., GCN 27958) is detected in a stacked image. Preliminary photometry of the afterglow is following Date       UT start  t-T0    Filter Exp.   OT    Err. UL                     (mid, days)     (s) 2020-06-19 18:58:23  6.58142 R      29*120 21.06 0.09 23.6 The photometry is based on nearby SDSS star SDSS-DR12_id      R(Lupton) J101207.75+454443.4 17.877 A light curve of the afterglow of  GRB 200613A can be found in http://grb.rssi.ru/GRB200613A/GRB200613A_lc_v2.png