TITLE: GCN CIRCULAR NUMBER: 8516 SUBJECT: GRB 081102: MASTER refind and final results DATE: 08/11/11 15:50:10 GMT FROM: Vladimir Lipunov at Moscow State U/Krylov Obs E. Gorbovskoy, V. Lipunov, V.Kornilov, A.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa Sternberg Astronomical Institute, Moscow State University A. Tlatov, A.Parkhomenko Kislovodsk Solar Station of the Pulkovo Observatory V.Krushinski, I.Zalognikh Ural State University, Kourovka S.Yazev, K.Ivanov Irkutsk State University Two of the four MASTER Very Wide Field Cameras located at Kislovodsk (http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix) has observed the Swift-BAT GRB081102 error box (Mangano et al., GCN Circ 8470, Lipunov et al., GCN 8464, 8471) with 5s exposures during all night without time gap between images. There are two separeted (~702m) mount with double cameras. Now we present results from the North and South mounts. These unfiltered images are calibrated relative to Tycho stars (V). We do not detect any new source at the XRT position reported in GCN Circ. 8470 (Mangano et al.) brighter than 13.0 mag before and after trigger time. The photometry results +-4 min around trigger time: T-T_trigger m_lim (S/N=3) Exposure Coadd -255s... 0... 255 s 11.8 5s yes -2min...0...+2 min 12.7 2x30s 12 -2min...0...+2 min 13.0 2x60s 24 The optical fluence during the 40s-GRBurst is limited by <= 1.6x10_-8 erg/cm_2 including 2.8 magnitude absorbtion (Ukwatta et al., Circ 8462). The BAT-fluence is aboute 2.3x10_-6 erg/cm_2 (15-150 keV) (Fenimore et al., GCN 8468). So: Optical Fluence/Gamma-Fluence(15-150keV) ~ < 1/140 Same ratio for GRB080319B is ~ 1/25 (Naked Eye GRB) in 15-150 keV (Racusin, Karpov et al., Nature, vol.455, 183, 2008). Scientific Master Team Report are available at http://observ.pereplet.ru/images/GRB081102/grb_film.html Note: the GRB was at the edge of the FOW in both cameras. The message may be cited. mailto: lipunov@sai.msu.ru