GCN Circular 4118
V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy, A.Krylov, G.Borisov, A.Sankovich, V.Vladimirov Sternberg Astronomical Institute, Moscow Union 'Optic' MASTER robotic system (http://observ.pereplet.ru) responded to GRB051021.6 at 2002-10-21 15:39:37 under the bad weather conditions after sunset. An automated response took the first image at 01h 28min after the GRB time. The unfiltered image is calibrateds relative to USNO A2.0 (0.8 R + 0.2 B). The robot not find OT-candidate in error box. Our upper limit is about 14.0 m. The reduction is continuing. The JPG-image will be available at http://observ.pereplet.ru/images/GRB051021.6/1.jpg . This work is supported by RFFI 04-02-16411 grant. This message can be cited.