TITLE:   GCN CIRCULAR
NUMBER:  13168
SUBJECT: Swift trigger 518853: MASTER-ICATE possible OT
DATE:    12/03/29 12:37:09 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc@observ.inetcomm.ru>

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)


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

K.Ivanov, S.Yazev, N.M.Budnev, O.Gres, O.Chuvalaev, V.A.Poleshchuk
Irkutsk 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.Krushinski, I.Zalozhnich,  A. Popov, A. Bourdanov, A. Punanova
Ural Federal University


MASTER-ICATE robotic Very Wide Field (http://93.180.27.230:8080/) located 
in Argentina was pointed to the area of the Trigger 518853 (Barthelmy et 
al., GCN  Circ 13166) several minutes before 
notice time (due to Swiwt pointing info) and 12.9 min  after GRB
time at 2012-03-29 02:34:16.391.

We find OT with Mag= 13.2 (unfiltered red CCD) at

    Ra=188.552513    Dec -63.417673
    Ra 12:34:12.60   Dec -63:25:03.62

With 25" sec 3-sigma error box. 
Thre is 2MASS nonstar object 12340720-6325129 with 1.2 arcsec offset.
That is inside XRT error box.

The absence OT in UVOT data may be connected with very high reddening of 
the source by Galactic extinction and distinction in time observations.

The follow up IR observations are requied to chose between CR or 
High Energy Transient nature (Evans and  Osborne, GCN Circ 13167) of the 
event.


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