[vsnet-grb-info 14565] GRB 140219A: MASTER optical brightening inside XRT-5 error box detection

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15879
SUBJECT: GRB 140219A: MASTER  optical brightening inside  XRT-5 error box detection
DATE:    14/02/23 15:59:55 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc at observ.inetcomm.ru>

V. Lipunov, M. Pruzhinskaya, E. Gorbovskoy, D.Denisenko, V.Kornilov, 
N.Tyurina, P.Balanutsa, A.Kuznetsov, V.V.Chazov, D.Kuvshinov
Lomonosov Moscow 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.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)

We refined our reduction of images started 18h 22m after trigger time 
(Gorbovskoy et al., GCN 15871). We  found  the 3-sigma OT on several (at 
least 4) best unfiltered images with limit ~ 20 mag inside XRT error box 
(Mangano  and Evans, GCN 15875) at automatic position:


2014-02-20 14:08:50.873 	10h 24m 06.46s , +06d 29m 40s.8

with 2 arcsec  error (2 arcsec = 1 pix).

The unfiltered magnitude is about 19.

Fortunately we have archive images of this area at the same telescope 
with slightly better limit(MASTER II, Tunka,2011-02-06 16:34:55 
180) without any optical source. The OT is brighter at least 1 magnitude 
at 18.5 hours after trigger.

The OT position does not coincide with  SDSS J102406.58+062945.7 galaxy 
(Singer, iPTF  GCN 15878, source XRT 5), closer to SDSS star
J102406.41+062937.6 .

The detection and reference images are  available at
http://master.sai.msu.ru/static/GRB/GRB140219A_OT.png

We do not see any OT at alert Very Wide Field images at this place 
(Gorbovskoy et al., GCN 15871).

The message may be cited.