[vsnet-grb-info 16175] GRB 150212A: MASTER optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17456
SUBJECT: GRB 150212A: MASTER optical observations
DATE:    15/02/12 13:22:42 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

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

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

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.Krushinsky, I.Zalozhnih,  A. Popov
Ural Federal University, Yekaterinburg, Kourovka

D.Buckley, S. Potter, A.Kniazev, M.Kotze
South African Astronomical Observatory

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  GRB150212A (Page et. al. GCN 17449) 
32 sec after notice time and 47 sec after trigger time at 2015-02-12 
10:58:06 UT in two polarization. Unfortunately we were unable to obtain 
satisfactory data on the first images due to clouds and high zenith 
distance (z~75 d).

In the process of further observations we do not see the optical transient 
and obtained the following upper limits:

T_start   T-Tmid Expt.   Mlimit
11:08:50  761     140      11.5
11:11:52  958     170      11.5
11:15:26  1177    180      12.5
11:26:34  1845    180 	   12.6
11:32:12  2183    180      15.0
11:32:12  3447   1800      16.7
11:35:58  2641    540      16.1

So weak upper limits associated with the observation through clouds and 
large zenith distance of the object.