[vsnet-chat 3428] Re: Permanent Superhumpers...

[Taichi Kato <tkato>]

Re: [vsnet-chat 3427] Re: Permanent Superhumpers...

> As far as I know Joe Patterson first used this term in the 1991 paper on
> V603 Aql (Patterson & Richman, 1991, PASP, 103, 735). Osaki (1989, PASJ,
> 41, 1005) indeed predicted the presence of permanent superhumps, however
> his exact words were: `CVs which are permanently stuck in the high tidal
> torque stage (in a permanently superoutbursting stage with superhumps)'. 
> So, he didn't use specifically the term `permanent superhumps', but the
> fame is his forever for the prediction.

   As I understand, exactly speaking, "permanent superhumps" and "permanent
superhumpers" are a different entity.  An object can show "permanent"
superhumps, in constrast to dwarf nova superhumps, when a certain instability
condition -- it's not a great surprize since there had been already a number
of calculations (dating back to Whitehurst 1988) which determine the
instability criterion.  This possibility was sought by several authors,
including Osaki 1989 [I personally thought of one for V795 Her, too]
However, the concept of "permanent superhumpers" is in the framework of
Osaki's unified theory.  At that time of our knowledge, it was a surprize
to find systems (other than postnovae) below the period gap, which can
permanently attain high-mass transfer to exhibit superhumps.  It is still
a mystery, as you know.  Although there was a suggestion of superhumps,
there had been a long standing discussion between models of intermediate
polars and preceessing disks to explain the phenomenon (e.g. see the
history of V795 Her).  As I understand, the final unambiguous solution
was achieved by Osaki's unification theory and his numerical simulations
with Hirose and Ichikawa, powered by the discovery of ER UMa stars in 1994,
the "missing link" between SU UMa stars and supposed permanent superhumpers.
The concept of "permanent superhumpers" was thus established by Osaki's
theory.  When we speak of permanent superhumps in long-period novalike
systems, we don't usually use the category "permanent superhumpers".

Regards,
Taichi Kato

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