TITLE: GCN CIRCULAR NUMBER: 27850 SUBJECT: GRB 200524A: Assy continued optical observations DATE: 20/05/29 08:45:32 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), V. Kim (AFIF, Pulkovo Observatory), A. Pozanenko (IKI), M. Krugov (AFIF), E. Mazaeva (IKI), A. Volnova (IKI) report on behalf of larger GRB IKI FuN collaboration: We observed GRB 200524A (Dirirsa et al., GCN 27797; Pookalil et al., GCN 27809; Capalbi et al., GCN 27811; Gupta et al., GCN 27818) with AZT-20 1.5 m telescope of Assy-Turgen observatory starting on May. 27 (UT) 17:29:53 in r'-filter. Optical afterglow discovered by ZTF (Ho et al., GCN 27799) and observed by several observations (Kumar et al., GCN 27800; Rumyantsev et al., GCN 27802; Sanwal et al., GCN 27803; Perley et al., GCN 27805; Kumar et al., GCN 27806; de Ugarte Postigo et al., GCN 27807; Blazek et al., GCN 27810; Ogawa et al., GCN 27813; Izzo, GCN 27817; Belkin et al., GCN 27820; Kuin et al., GCN 27825). Preliminary photometry of the afterglow is following Date UT start t-T0 Filter Exp. OT Err. UL (3sigma) (mid, days) (s) 2020-05-27 17:29:53 3.55617 r'(AB) 110*60 22.80 0.17 24.4 The photometry is based on the nearby stars of PS1 catalog.