TITLE:   GCN CIRCULAR
NUMBER:  13848
SUBJECT: GRB 121011A: MASTER-Net early OT light curve
DATE:    12/10/11 13:10:07 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

V.Yurkov, Yu.Sergienko, D.Varda, E.Sinyakov
Blagoveschensk Educational State University, Blagoveschensk

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk State University

E. Gorbovskoy, V. Lipunov, V.Kornilov, D.Kuvshinov, A.Belinski, N.Tyurina, 
N.Shatskiy, P.Balanutsa, D.Zimnukhov, A.Kuznetsov,  V.V.Chazov, A.Sankovich, 
D.Denisenko
Moscow Lomonosov State University, Sternberg Astronomical Institute,

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

V.Krushinski, I.Zalozhnich,  A. Popov, A. Bourdanov, A. Punanova
Ural Federal University

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

Claudio Mallamaci, Carlos Lopez and Federico Podest
Observatorio Astronomico Felix Aguilar (OAFA)

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru)
located in Blagoveschensk was pointed to the  GRB121011.47 10 sec s after
notice time and 51 sec after GRB time at 2012-10-11 11:16:21.301 UT in
two polarizations.
The 5-sigma upper limit  of the first (10s exposure) set  has been about
17.0 mag

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in Tunka was pointed to the  GRB 121011A   65 sec s after notice 
time and 106 sec after GRB time at 2012-10-11 11:17:14 UT in two 
polarizations. On our first 
(10s exposure) set we haven't found optical transient  within SWIFT 
error box. The weather conditions were not very good.

The first individual image on which we see the OT was taken on 2012-10-11 
at 11:19:20, i.e 230 sec. after the GRB time. The maximum brightness
(calibrated to 0.8*R+0.2*B from USNO-B1.0) was 16.1.

The preliminary light curve is available here:
http://master.sai.msu.ru/static/GRB/GRB121011_pre_lc.png

We note that nothing is visible at the position of the OT on the Palomar 
DSS plates and on color-combined SDSS image, implying the host galaxy is 
fainter than 22.5 m.

The reduction of the whole data set is continuing.

This message can be cited.