TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4990 SUBJECT: GRB060418: optical observations DATE: 06/04/21 14:00:18 GMT FROM: Alexei Pozanenko at IKI, Moscow B. Hafizov (MAO), D. Sharapov (MAO and NOT, La Palma), A. Pozanenko (IKI), M. Ibrahimov (MAO) on behalf of larger GRB follow up collaboration report: We observed the afterglow of GRB060418 (Falcone et al. GCN 4966) with 1.5m telescope of Maidanak Astronomical Observatory (MAO) in BRI-bands on April 18. A series of BRI images (B: 8x180s, R: 7x120s, I: 9x120s) were taken on April 18 (UT) 19:54 - 21:07 and 9x120s I-images were taken between 22:14 - 22:37. We detect OT (Falcone et al. GCN 4966) on single images in I and R; preliminary OT brightness estimation of the first I-image (UT=19:54) is ~20.5. Data reduction is continuing. This message may be cited.