TITLE: GCN GRB OBSERVATION REPORT NUMBER: 2002 SUBJECT: GRB030329:optical observations by MASTER DATE: 03/03/29 22:01:01 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs ITLE: GCN GRB OBSERVATION REPORT V. Lipunov, A.Krylov, V.Kornilov, G.Borisov, D.Kuvshinov, A.Belinski, I.Chilingarian, M.Kuznetsov, S.Potanin, V.Vitrischak, G.Antipov Sternberg Astronomical Institute, Alexsandr Krylov Observatory, Moscow We are observing the OT of GRB 030329 in R-band with MASTER system (280 mm, http://observ.pereplet.ru). We began observations at 17:15UT (~5h30m after GRB time). Optical source (about 13.6 in R) was detected at the position given in Circ 1985 in the beginning of observations. At 20:20UT (~8h40m after GRB time) magnitude became more than one magnitude fainter and it was about 14.8 in R. The OT seems to become fainter very slowly. At present we have about 100 images of the OT. These images are being processed. These are preliminary results.