TITLE:   GCN CIRCULAR
NUMBER:  19284
SUBJECT: GRB 160411A: MASTER-NET early optical observations.
DATE:    16/04/11 08:06:17 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

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

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

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

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

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

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)

R. Rebolo, M. Serra, N. Lodieu, G. Israelian, L. Suarez-Andres
The Instituto de Astrofisica de Canarias

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) 
located in SAAO was pointed to the  GRB160411A 34 sec after notice time 
and 64 sec after trigger time at 2016-04-11 01:30:00 UT. On our first (10s 
exposure)  set we haven`t found optical transient  within SWIFT error-box 
(Page et al GCN 19279, Evans et al GCN 19283).
The 5-sigma upper limit has been about 16.0 mag  on single (10 sec 
exposure) and 18.5  on coadd (170 sec exposure) image.
The observations made on high zenit distance (z=80 deg).
The message may be cited.