[vsnet-alert 7414] KK Tel: definite SU UMa-type dwarf nova with a long superhump period!

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

KK Tel: definite SU UMa-type dwarf nova with a long superhump period!

Dear Colleagues,

   Tom Richards reported a long time-series taken on June 20
(vsnet-campaign-data 98).  The long run has firmly established the
recurring 0.2 mag superhump signal (three maxima recorded).
Combined with the earlier data by Peter Nelson, we have been able
to determine the superhump period to be 0.08841(5) d.  This value
is one of the longest periods among SU UMa-type dwarf novae below
the period gap.  If we adopt the quiescent hump period of 2.02 hr
(Howell et al. 1991, PASP 103, 300), the fractional superhump
excess is about 5%, which is also one of the largest values among
known SU UMa-type stars.

   Considering that prominent hump feature is visible in quiescece,
the orbital inclination of this system is expected to be high.
At such a large inclination, we can expect significant beat modulations
between the orbital and superhump periods (as prominently seen in the
recent case of RZ Leo; see also Ishioka et al. (2001) PASJ 53, 905).
With the received paramters of KK Tel, the beat period is about 2 d.
This implies that the superhump profiles (amplitude, mean brightness)
can vary with this time-scale.  Nightly observations are therefore
very strongly encouraged.

Regards,
Taichi Kato
on helaf of the VSNET Collaboration team

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