TITLE:   GCN CIRCULAR
NUMBER:  18718
SUBJECT: V404Cyg Swift Trigger 668097: MASTER-Tunka optical wake up detection
DATE:    15/12/23 12:44:16 GMT
FROM:    Vladimir Lipunov at Moscow State U/Krylov Obs  <lipunov@xray.sai.msu.ru>

O. Gress, K. Ivanov, N.M. Budnev, V.A. Poleshchuk, S.A. Yazev
Irkutsk State University

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

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

We reported about V404 Cyg optical detection by MASTER-Amur (Yurkov et 
al., GCN 18717) after Swift BAT alert ( Barthelmy et al.,  18716).

MASTER-Tunka starts alert observations of V404 at 2015-12-23 10:16:20 UT 
(just after the sunset, 17447 sec after notice time and 17787 sec after 
trigger time).
  There is fast about half-magnitude variability at the interval about 
10min time scale.

Preliminary LC is available at 
http://master.sai.msu.ru/static/v404_23dec2015.png


  The message may be cited.