{
  "bibcode": "2008GCN..8471....1L",
  "body": "MASTER-Net Team (http://observ.pereplet.ru):\n\nV. Lipunov, V.Kornilov,  E.Gorbovskoy,\nA.Belinski, N.Shatskiy, N.Tyurina, D.Kuvshinov, P.Balanutsa\nSternberg Astronomical Institute, Moscow State University\n\nA. Tlatov, A.Parkhomenko\nKislovodsk Solar Station of the Pulkovo observatory\n\nV.Krushinski, I.Zalognikh\nUral State University, Kourovka\n\n\nS.Yazev, K.Ivanov\nIrkutsk State University\n\n\nMASTER Very Wide Field Camera located at Kislovodsk (2000 m)\n(http://apollo.sai.msu.ru/, D=50 mm, 4x1000 square degrees, 35'' per pix) \nhas observed the Swift-BAT GRB081102 error box  (Ukwatta et al., GCN Circ 8642) \nwith 5s exposures during all night without windows between images. \nThere are two  separeted (~702m) mount with double cameras.\n\nNow we present results from North camera.\n\nThese unfiltered images are calibrated relative to Tycho stars (V).\nWe do not detect any new source at the XRT position\nreported in GCN Circ. 8467 ( Osborne et al.) brighter than 12.4 mag \nbefore and after trigger time.\nThe photometry results +-4 min around trigger time:\n\n\n  T-T_trigger            m_lim (S/N=3)         Exposure         Coadd\n\n-255s... 0... 255 s       11.6                  5s              no \n-2min...0...+2 min        12.2                 30s               6\n-2min...0...+2 min        12.4                 60s              12\n\nThe optical fluence during the 60s-GRburst is limited by <= 6x10_-9 \nerg/cm_2    including 2.5 magnitude  absorbtion (Ukwatta et al., Circ \n8462). The BAT-fluence is aboute 3 10_-6 erg/cm_2 (15-150 Kev) \n(http://gcn.gsfc.nasa.gov/notices_s/333427/BA/).\nSo\n\nOptical Fluence/Gamma-Fluence ~ < 1/500\n\nSame ratio for GRB080319B is ~ 1/200 (Naked Eye GRB).\n\nThe  light curve  is available at\nhttp://observ.pereplet.ru/images/GRB081102/lc1.png\n\n\nThe  video  are available at\nhttp://observ.pereplet.ru/images/GRB081102/grb.gif\nYou can see 200 sets.\nNote: the GRB was at the edge of the FOW.\n\nThe reduction is continuing.\n\nmailto: lipunov@sai.msu.ru",
  "circularId": 8471,
  "createdOn": 1225742802000,
  "email": "gcncirc@observ.inetcomm.ru",
  "subject": "GRB 081102: MASTER prompt optical limit",
  "submitter": "Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>",
  "eventId": "GRB 081102"
}