TITLE:   GCN CIRCULAR
NUMBER:  15960
SUBJECT: GRB 140311B: final MASTER OT light curve
DATE:    14/03/12 10:53:33 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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


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

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

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

V.Krushinski, I.Zalozhnih,  A. Popov
Ural Federal University, Kourovka

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 Tunka was pointed to the  GRB140311B  (Racusin et al., GCN 
15945) 29 sec after notice time and 107 sec after trigger time (Gorbovskoy 
et. al GCN 15948 ) and  made observations during ~ 1.5 h before sunrise.
We see OT  (Xu et. al.  GCN 15949) only on several coadditional images. On 
all of them the object is close to  limit  and has s/n from 3 to 6.
Our preliminary ligth curve available in table below and on image here 
http://master.sai.msu.ru/static/GRB/grb140311B.png.

T_start       T_t-T_m  Exptime   Mag.   Coadd
                 [s]     [s]      [m]
21:17:12        326      220     19.4     4
21:18:18        432      300     19.0     4
21:16:16        557      650     19.4     8
21:19:44        557      380     18.7     4
21:19:44        661      550     18.9     5
21:21:19        708      490     18.9     4
21:18:18        834      960     19.4     8
21:25:40       1485     1380     19.8     8
21:25:40       1702     1740     20.0    10

T_t is GRB trigger time, T_m is middle time of our exposure.
Our unfiltered magnitude is well described by a parity 0.8R + 0.2B (USNO 
B1)

The power low index alpha from 380 to 1740 seconds after the trigger  is 
1.07+-0.10  (F ~ t-apha).

We also apologize for an error in the title of our previous telegram (GCN 
15948) if it misled somebody.


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