[vsnet-alert 2192] V1028 Cyg

[Taichi Kato <tkato>]

Superoutburst of V1028 Cyg:

>Two little-known dwarf
>novae in Cygnus have just gone into superoutburst: V1028 and V630.
>The former was at 13.6 last night, the latter near 14.5.  We earnestly
>desire to know their superhump periods!

   V1028 Cyg is one of the most intensively observed SU UMa-type dwarf novae,
at the news of a rare outburst in 1995 July-August, which may be still
fresh in reader's mind.  The superhump period and its evolution was very
exactly determined and followed (thanks to the quite exceptional bunch of
clear nights at Ouda Station!).  The object is one of rare "positive Pdot"
systems, which show increasing superhump periods during superoutburst,
contrary to the well-known canonical decrease of superhump periods.
The details of photometry (Baba et al.) during the 1995 superoutburst is
available from the VSNET server:

   http://ftp.kusastro.kyoto-u.ac.jp/pub/vsnet/preprints/V1028_Cyg

   This outburst was also remarkable in that it showed a prominent post-
superoutburst rebrightening.  It would be interesting to see whether the
same features repeat in the present superoutburst.

   The exact nature of V630 Cyg is less well known, but the following URL
may be of interest.

   http://vsnet.kusastro.kyoto-u.ac.jp/vsnet/DNe/v630cyg.html

   Superoutbursts of V630 Cyg being relatively frequent, I would recommend
potential observers to focus on V1028 Cyg.  And for northern larger scopes
and CCDs, V592 Her still remains a fascinating target.  The object stays at
around 16.0, apparently in superoutburst plateau, and we have no assurance
that we can experience a similar phenomenon within the next decade.
We will be prettey sure V1028 Cyg and V630 Cyg will undergo superoutbursts
within years.

Regards,
Taichi Kato

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