[vsnet-grb-info 19343] GRB170426.95 MASTER-Net OT detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  21040
SUBJECT: GRB170426.95 MASTER-Net OT detection
DATE:    17/04/27 00:54:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov at xray.sai.msu.ru>

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

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

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

V. Yurkov, A. Gabovich, Yu. Sergienko
Blagoveschensk Educational State University, Blagoveschensk

R. Podesta, Carlos Lopez and F. Podesta
Observatorio Astronomico Felix Aguilar (OAFA)

Hugo Levato and Carlos Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

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

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

MASTER II  robotic telescope (MASTER-Net: http://observ.pereplet.ru) located in Kislovodsk was pointed to the  GRB170426.95 894 sec after notice time and 982 sec after trigger time at 2017-04-26 23:00:43 UT. On our 6-th (180s exposure)  set we  found 1 optical transient within SWIFT error-box (ra=184.879 dec=5.65583 r=0.066667) brighter then 18.91.


 T-Tmid      Date      Time       Expt.        Ra                Dec           Mag
---------|---------------------|-------|-----------------|-----------------|-------
    1072   2017-04-26 23:00:43     180   (12h 19m 39.17s , +05d 37m 42.5s)    16.08

The 5-sigma upper limit has been about 18.91mag
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