[vsnet-grb-info 16206] GRB 150222A: MASTER early optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17487
SUBJECT: GRB 150222A: MASTER early  optical observations
DATE:    15/02/22 17:19:12 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  GRB150222A  58 sec after notice time 
and 76 sec after trigger time at 2015-02-22 16:57:57 UT in two 
polarizations. On our first (10s 
exposure)  set we haven`t found optical transient  within SWIFT error-box 
(Bernardini  et. al GCN 17486).
The 5-sigma upper limit has been about 15.5 mag
The observations  made on high zenith distance (z=75 d).
The message may be cited.