[vsnet-grb-info 12417] GRB 120919B: MASTER prompt optical observations

[GCN Circulars]

TITLE:   GCN CIRCULAR
NUMBER:  13792
SUBJECT: GRB 120919B: MASTER prompt optical observations 
DATE:    12/09/21 13:54:00 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <gcncirc at observ.inetcomm.ru>

H. Levato and C. Saffe
Instituto de Ciencias Astronomicas, de la Tierra y del Espacio (ICATE)

C. Mallamaci, C. Lopez and F. Podest
Observatorio Astronomico Felix Aguilar (OAFA)

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

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

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

V. Krushinski, I. Zalozhnich,  A. Popov, A. Bourdanov
Ural Federal University


MASTER-ICATE robotic Very Wide Field Cameras (FOV=2x384 square degrees,
D=72mm, f/1.2, 1 pix = 22 arcsec, http://observ.pereplet.ru) located in
Argentina (Observatorio Astronomico Felix Aguilar,
http://93.180.27.230:8080/) were pointed to the GRB120919B by FERMI 
369710066 trigger   30 s after notice time and 55 s after GRB time at 
2012-09-19 01:15:18 UT.
We cover full IPN-triangulations error-box (K. Hurley et. al. GCN13788)
We haven`t found  optical transient  within IPN-triangulations error-box
   our first (5 s exposure) set and on coadd image with complete exposure
of 45 seconds durnig gamma-burst activity (Golenetskii et al., GCN 13789).

The 5-sigma upper limit on single image has  been about 11.7 mag and 12.5 
mag on coadded image.

Also, we are marginaly see ~2 sigma OT at position Ra 20:10:26.40 Dec 
+37:31:48.00 with magnitude 12.5+-0.5m .

The coverage map and OT image available here 
http://master.sai.msu.ru/static/GRB/GRB120919B_2x2deg.png

Our cameras are continuously imaging the sky with 5 sec exposures.

This message can be cited.