TITLE:   GCN CIRCULAR
NUMBER:  16074
SUBJECT: GRB 140402A: MASTER optical observations
DATE:    14/04/03 11:53:03 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, M. Pruzhinskaya, D.Denisenko, V.Kornilov, 
N.Tyurina,
P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov
Lomonosov Moscow State University, Sternberg Astronomical Institute

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 Blagoveschensk was pointed to the  GRB140402A (Jenke et. al GCN 
16070) ~ 13.6h  (49103 sec) after trigger time at 2014-04-02 13:48:30 UT 
directly after sunset and the weather conditions became good.
We haven`t found optical transient  within Fermi-LAT  (Bissaldi et. al. 
GCN 16069)  and SWIFT-BAT (Cummings et. al GCN 16073) error-boxes on 
single and coadd images.
The 5-sigma unfiltered upper limit has been about 18.2 mag on single (180 
s) image and about 19.8 on coadd of 10 images with total exposure 1800 s.

Also MASTER II  robotic telescope  located in Kislovodsk was twice pointed 
to this GRB by FERMI-GBM two alert coordinates 23 s and ~ 1h after trigger 
time. But the final Fermi-LAT and SWIFT-BAT position is out of our FOV due 
to big coordinates errors.

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