[vsnet-alert 1208] Re: USNO 1425.09823278

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

Dear Tonny,

> >reported on Sep. 10 may represent the fading from a normal outburst which
> >subsequently triggered the presently lasting (presumable) superoutburst.
> 
> If the outburst before Sep 10th was a normal outburst i.s.o. a superoutburst,
> then how does this fit with the observation of superhumps BEFORE Sep 10th ?

    The first outburst which ended on Sep. 8 was a genuine superoutburst,
as many observers detected superhumps.  Then the system had a drop in
brightness (sometimes called as "dip"), and rose again on Sep. 10.  On
the very first night of the rebrightening, the superhump signal was very
weak, at most ~0.05 mag as several observers reported, and the system
showed a rapid decline as you mentioned in CVC.  The object then rose up
again, as visual observations suggest, being accompanied with more prominent
superhumps as L. T. Jensen observed.  This course is quite similar to that
observed in AL Com in 1995 around and after the "dip".  A close description
is given in Nogami et al. (1997) ApJ in press, whose preprint is avialable
from the VSNET preprint directory.  The existtence of superhumps during the
precursor outburst (even if it looks loke a normal outburst) is not uncommon,
just as was observed in T Leo in 1993.  This preprint (T. Kato, 1997, PASJ
in press) is also available from the VSNET preprint directory.

Regards,
Taichi Kato

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