[vsnet-grb-info 16395] Fermi trigger 449861706: MASTER-SAAO possible candidate to OT of Short GRB

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  17676
SUBJECT: Fermi trigger 449861706: MASTER-SAAO possible candidate to OT of Short GRB 
DATE:    15/04/04 22:24:45 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

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

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

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

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

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 SAAO was pointed to the  GRB150404.73 (Fermi trigger 449861706) 
8 sec after notice time and 41 sec  after trigger time at 2015-04-04 17:35:45 UT.

On our first (10s exposure)  set we  found 1 optical transient within 
FERMI error-box
(ra=11 05 45 dec=-69 34 46 r=9.720000) in one polarization:

MASTER OT J110859.75-693818.9
RA  = 11h 08m 59.75s
Dec = -69d 38m 18s.9
  m_OT=14.8.

We have 2 pair images in 2 different polarization. The first pair started 
2015-04-04 17:35:45 , 10s exposition. The second pair (20-s exposition) 
started on 2015-04-04 17:36:25, and there is no optical candidate on it.
The 5-sigma upper limit has been about 15.8 mag.

The possible OT image is available at 
http://observ.pereplet.ru/GRB150404.73.jpg
The message may be cited.