[vsnet-grb-info 14669] GRB 140311C: MASTER optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  15983
SUBJECT: GRB 140311C: MASTER optical observations 
DATE:    14/03/14 15:01:38 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc at observ.inetcomm.ru>

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

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

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)


As previously reported (Yurkov et. al. GCN 15981) MASTER VWF robotic very 
wide field cameras (FOV=2x384 square degrees, D=72mm, f/1.2, 1 pix = 22 
arcsec) installed on  MASTER-II robotic telescope in Tunka covered full 
FERMI GBM error-box (M. Stanbro, GCN15977)  before, during and after GRB. 
We haven`t found credible optical transient with 3-sigma  upper limit 
10.5m.
We also didn't find credible optical counterpart on the survey (Yurkov et. 
al. GCN 15981) of part of error box carried out directly after GRB on 
MASTER-II robotic telescope up to 18 mag.

The synchronous move of FERMI GBM error-box available here
http://master.sai.msu.ru/static/GRB/GRB140311C_FERMI.gif
http://master.sai.msu.ru/static/GRB/GRB140311C_diff.gif
The circle on move  is the Fermi GBM 1 sigma+3 degrees systematic error 
box.

Also   very wide field cameras covered a place of possible iPTF 
counterpart (Singer et. al. GCN 15971).
Unfortunately the bright star is projected into OT place. We didn't find a 
noticeable brightening of this star.
The syncronous move from  very wide field cameras of possible iPTF 
counterpart place available here
  http://master.sai.msu.ru/static/GRB/GRB140311C_IPTF.gif
This place was not  covered on MASTER-II survey.

The Prompt Optical to Gamma Fluence  Ratio during this burst is:
F_opt/F_gamma <~  1 : 820.

The covarege map is available at 
http://master.sai.msu.ru/static/GRB/GRB140311C_map1.png .

The message may be cited.