[Message Prev][Message Next][Thread Prev][Thread Next][Message Index][Thread Index]

[vsnet-alert 172] superhumps of V1028 Cyg



V1028 Cyg

    We obtained four hours' CCD photometry between July 30.63 and 30.81.
The light curve clearly indicates that "true" superhumps have grown.
The amplitude of superhumps has grown to 0.07 mag, with a familiar single-
peaked hump structure.  A prelimiary period analysis yields the best estimate
of the superhump period as 0.065 +/- 0.001 day (slightly affected by short
duration of the run).  It is curious that the period reported for July 29
observations was significantly longer.  We have re-analyzed the last night'
data, by selecting high S/N data, and obtained a period of 0.070 +/- 0.001
day, which is still longer than the current value.  We can not say at this
time the cause of this discrepancy in periods.  (An analysis of merged data
set of these two nights shows marked periodicities at 0.0661 and 0.0704
day.)  Of course this may be caused by limited duration of observations,
intrinsic irregularity, unstable periodicity at the growing stage of super-
humps, co-existence of double periods, etc.  We should wait further obser-
vations to check these possibilities.

    Anyway, we can now firmly say that V1028 Cyg is a genuine member of
SU UMa-type dwarf novae.  We will be observing for coming nights to follow
the development of superhumps.

Regards,
Taichi Kato & Ouda Team

VSNET Home Page

Return to Daisaku Nogami


vsnet-adm@kusastro.kyoto-u.ac.jp