GCN Circular 8516
Subject
GRB 081102: MASTER refind and final results
Event
Date
2008-11-11T15:50:10Z (17 years ago)
From
Vladimir Lipunov at Moscow State U/Krylov Obs <gcncirc@observ.inetcomm.ru>
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