TITLE: GCN CIRCULAR NUMBER: 29208 SUBJECT: GRB 201227A: Chilescope optical observations, possible optical counterpart DATE: 20/12/30 21:14:02 GMT FROM: Alexei Pozanenko at IKI, Moscow S. Belkin (IKI), A. Pozanenko (IKI), M. Krugov (FAI), P. Minaev (IKI) report on behalf of GRB IKI FuN collaboration: We observed the field of XRT 1-3 sources (D'Elia et al., GCN 29202) (hereafter X1,X2,X3) found in IPN localization area (Svinkin et al., GCN 29182) of GRB 201227A (Ursi et al., GCN 29179; Xiao et al., GCN 29187; Svinkin et al., GCN 29196; Lesage et al., GCN 29206) with Chilescope RC-1000 starting on 2020-12-29 (UT) 04:02:05 in r'-filter. The X3 source was observed by one 300 s exposure, and the filed of X1,X2 was observed by 3*300 s exposure. The limiting magnitude of single exposure of X3 and the stacked 3*300 s exposure is about r'=20.9. There are two optical sources close or on the edge of the XRT error circle localization of X3. Both sources are present in USNO-B1.0 and our photometry of the sources show no excess in brightness in comparison with any R-mag of USNO-B1.0. Also there are two optical sources close or on the edge of the XRT error circle localization of X1. Both source are also present in USNO-B1.0 and our photometry of the sources show no excess in brightness in comparison with any R-mag of USNO-B1.0. At the edges of X2 error circle we found two sources which not presented in USNO-B1.0. The coordinates of the first one (X2_O1) is RA(J2000)=11h 22m 29.34s, Dec(J2000)=-73d 28’ 44.9’’. The photometry of the source is r'= 20.50 +/-0.29 and the source is barely visible in DSS2 plate. The coordinates of second one (X2_02) is RA(J2000)=11h 22m 27.94s, Dec(J2000)=-73d 28’ 50.6’’. The photometry of the source is r'= 20.52 +/-0.29 and the source is not presented in DSS2 plate. We may suggest the optical object X2_02 could be a counterpart of GRB 201227A. The photometry is based on nearby stars from the APASS_DR8 and still preliminary RA DEC r 11:19:31.40904 -73:35:47.6880 14.090 11:19:44.89128 -73:34:49.6092 15.180 11:19:36.65304 -73:36:30.2112 15.307 Taking into account that early more deep observations of the IPN field by GRAWITA VST-ESO PARANAL (Izzo et al., GCN 29207) does no show any counterpart we may suggest the X2_O2 source (RA(J2000)=11h 22m 27.936s, Dec(J2000)=-73d 28’ 50.55’’) is a possible optical counterpart or kilonova of GRB 201227A.