TITLE: GCN GRB OBSERVATION REPORT NUMBER: 4173 SUBJECT: GRB051028:MASTER observations DATE: 05/10/28 21:29:54 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs V. Lipunov, V.Kornilov, D.Kuvshinov, N.Tyurina, A.Belinski, E.Gorbovskoy, A.Krylov, G.Borisov, A.Sankovich, G. Antipov, V.Vladimirov Sternberg Astronomical Institute, Moscow Union 'Optic' MASTER robotic system (http://observ.pereplet.ru) responded to HETE GRB051028.6 (GCN 4172). An automated response took first image 2005-10-28 16:59:56 UT, 03h 23 m after the GRB time (GCN4171). The unfiltered image is calibrated relative to USNO A2.0 (0.8 R + 0.2 B). We not find OT-candidate in error box brighter then 17.9 on the summ of 9 images between 17 32 40 - 18 03 03 UT. Mean time is 17 48 09 ( 4 h 12 min after GRB Time). The JPG-image of the summ will be available at http://observ.pereplet.ru/images/GRB050828/1.jpg (In error circ you can see candidates which we recognised with 2MASS ). The reduction is continuing. This work is supported by RFFI 04-02-16411 grant. This message can be cited. Mailto: lipunov@sai.msu.ru