[vsnet-alert 9521] Re: Possible new variable star in Cygnus = OT_J193640.95+332606.3

[Taichi Kato]

Re: Possible new variable star in Cygnus = OT_J193640.95+332606.3

   Although it is very difficult to make any firm conclusion,
the blue (R ~ B) color seems to suggest a cataclysmic variable in
outburst.  The coordinates of the object and the USNO star seem
to be slightly different, possibly suggesting that they are different
objects and the the quiescent counterpart is below the POSS detection
limit.

   Keeping them in mind, the overall light curve indeed looks like
that of a fading dwarf nova outburst.  The reported short-term
modulations don't very much look like superhumps.
The mean decline rate (close to 0.2 mag/d) is also slightly too
large for a superoutburst, but there remain a possibility that
the initial point represents rapidly decaying stage of a WZ Sge-type
superoutburst.  If this is the case, the apparent lack of clear
superhumps (as yet) may be explained, since regular superhumps
in these systems appear one or two weeks after the initial peak.
There seem to be sufficient opportunity to see superhumps to develop
(or remaining early superhumps), and we would encourage further
time-resolved photometry unless the object is proven to be otherwise.