[vsnet-grb-info 8543] GRB 091020: MASTER optical transient polarimetry

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  10052
SUBJECT: GRB 091020: MASTER optical transient polarimetry 
DATE:    09/10/21 05:15:37 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc at observ.inetcomm.ru>

E. Gorbovskoy,D.Kuvshinov, V. Lipunov, V.Kornilov, D.Kuvshinov,
A.Belinski,  A. Krylov, N.Shatskiy, N.Tyurina, P.Balanutsa, V.V.Chazov,

Sternberg Astronomical Institute, Moscow State University

A. Tlatov, A.V. Parkhomenko, D. Dormidontov
Kislovodsk Solar Station of the Pulkovo Observatory

V.Krushinski, I.Zalognikh, T.Kopytova, A. Popov
Ural State University, Kourovka

S.Yazev, K.Ivanov, N.M.Budnev
Irkutsk State University

V.Yurkov
Blagoveschensk Educational State University, Blagoveschensk

MASTER II robotic telescope (MASTER-Net: http://observ.pereplet.ru, 2x400 
mm, 8 square degrees, 2x16Mpx Apogee CCD) located
at Kislovodsk  was pointed to the  GRB 091020 (Racusin et al., GCN 10048) 
by internet   3422 s after the GRB time. The 
large delay  was caused with   technical problems on site.

We see bright optical counterpart (~17.5 mag) on the firrst images at UVOT 
position.

We have 130  images with 180 sec synchronous exposition each and 19.5 
magnitude limit during ~4 hours in two polarization.

The power low decay with alpha ~= 1.3 during  2.5 hours is observed. 
This is the preliminary result.
The reduction is continued.



The message may be cited.

mailto: lipunov at sai.msu.ru