TITLE: GCN CIRCULAR NUMBER: 27978 SUBJECT: GRB 200613A: Mondy optical observations DATE: 20/06/18 10:44:12 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI),  A. Pozanenko (IKI), E. Klunko (ISTP),  M. Eselevich (ISTP), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of IKI-GRB FuN: 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 with AZT-33IK 1.5-m telescope of Sayan observatory (Mondy) starting on 2020-06-17 (UT) 16:30:12. 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) 2020-06-17 16:30:12  4.47365 R      22*120 20.94 0.14 22.1 The photometry is based on nearby SDSS stars SDSS-DR12_id      R(Lupton) J101206.52+454606.4 14.962 J101207.75+454443.4 17.877 J101206.50+454322.2 15.151