MASTER-Net Science Release
25 apr 2009
on prompt optical observations of the GRB 090424
Publications: GCN 9252, GCN 9233
Optical 1s frame limits. Time calculated
from Fermi GBM Trigger Time = 14:12:08.67 (Connaughton, GCN
9230). 1% coincident with our start zero image time.
3x3 degrees around Swift XRT
position. 1s exposure each frame.
3x3 degrees around Swift XRT
position. 6s exposure each frame.
6x6 degrees around Swift XRT
position. 60s exposure each frame.
TITLE: GCN CIRCULAR
NUMBER: 9252
SUBJECT: GRB 090424: MASTER-Net prompt optical limit
DATE: 09/04/25 20:29:42 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, V.V.Chazov, P.V.Kortunov, A.Kuznetsov
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, S.Yazev
Irkutsk State University
A. Tlatov, A.V. Parhomenko,
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalognikh, T.Kopytova
Ural State University, Kourovka
There are 6 MASTER Very Wide Field cameras located at Kislovodsk and Irkutsk
with common FOW = 6000 square degrees (http://observ.pereplet.ru/).
One of the two MASTER Very Wide Field Cameras located at Irkutsk
(D=50 mm, 2x1000 square degrees, 11 Mpx, 72" per pix in binning regime) has
observed UVOT error box (Cannizzo et al., GCN 9223) with 1s exposure
befoure,
during and after GRB Time without time gap between images.
The error box is near at the center of our FOW.
Our unfiltered images are calibrated relative to Tycho stars (V) and very
close to V band.
The magnitude limit of the each emage is ~8 m at the center of FOW (some
cloudy on the sky). The limit of coadded six images ~ 9 m.
We do not detect OT.
Our observations results:
----------------------------------------------------------------------
Fermi GRB Trigg.* Exposure Mag Limit Optical Flux Coadd?
time (sec) (sec) (m) (erg/sm^2 s)
----------------------------------------------------------------------
-2 1 8.1 1.3x10^-8 No
-1 1 8.1 1.3x10^-8 No
0 1 8.0 1.4x10^-8 No
+1 1 8.0 1.4x10^-8 No
+2 1 8.0 1.4x10^-8 No
+3 1 7.9 1.5x10^-8 No
+4 1 8.0 1.4x10^-8 No
+5 1 8.0 1.4x10^-8 No
-60 : +120 1 ~8 ~1.4x10^-8 No
-6 6 8.9 7.0x10^-9 Yes
+0 6 8.7 7.3x10^-9 Yes
+6 6 8.8 7.2x10^-9 Yes
+12 6 8.9 7.0x10^-9 Yes
-60 60 9.7 3.0x10^-9 Yes
0 60 9.7 3.0x10^-9 Yes
60 60 9.5 3.5x10^-9 Yes
-----------------------------------------------------------------------
*Fermi GBM Trigger Time = 14:12:08.67 (Connaughton, GCN 9230) 1%
coincident with our start zero image time.
1). the optical fluence during GRBurst is limited by
0 up to +6 s ~<= 1 x 10E-7 erg/cm^2
0 up to +60 s <= 5 x 10E-7 erg/cm^2
including total absorbtion 1 magnitude in V band.
(The absorption column density NH = (0.20 +/- 0.01) x10^22 cm^-2
from Swift XRT spectrum data, Margutti, GCN 9237).
The event fluence (8-1000 keV) in this time interval is
(5.2 +/- 0.1)E-05 erg/cm^2 (Connaughton, GCN 9230).
So:
2).
Optical-Fluence(6s)/Gamma-Fluence (8-1000 keV) ~ < 1/500
Optical-Fluence(60s)/Gamma-Fluence(8-1000 keV) ~ < 1/100
The same ratio for GRB080319B is
Optical-Fluence/Gamma-Fluence(8 - 1000 keV) ~ 1/140
(Naked Eye GRB, Racusin, Karpov et al., Nature, vol.455, 183,
2008).
The light curve and film of our observations is available at
http://observ.pereplet.ru/images/GRB090424/GRB090424.html
The reduction is continued.
The message may be cited.
mailto: lipunov@sai.msu.ru
TITLE: GCN CIRCULAR
NUMBER: 9233
SUBJECT: GRB 090424: MASTER-Net prompt optical observations
DATE: 09/04/24 21:01:23 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, V.V.Chazov, P.V.Kortunov, A.Kuznetsov
Sternberg Astronomical Institute, Moscow State University
K.Ivanov, S.Yazev
Irkutsk State University
A. Tlatov, A.V. Parhomenko,
Kislovodsk Solar Station of the Pulkovo Observatory
V.Krushinski, I.Zalognikh, T.Kopytova
Ural State University, Kourovka
There are 6 MASTER Very Wide Field cameras located at Kislovodsk and Irkutsk
with common FOW = 6000 square degrees (http://observ.pereplet.ru/).
One of the two MASTER Very Wide Field Cameras located at Irkutsk
(D=50 mm, 2x1000 square degrees, 11 Mpx, 72" per pix in binning regime)
has observed UVOT error box (Cannizzo et al., GCN 9223) with 1s exposure
befoure, during and after GRB Time without time gap between images.
The error box is near at the center of our FOW.
Our unfiltered images are calibrated relative to Tycho stars (V).
The magnitude limit of the each emage is ~8 m at the center of FOW (some
cloudy on the sky). The limit of coadded five images ~ 9 m.
The reduction is continued.
The message may be cited.
mailto: lipunov@sai.msu.ru