[vsnet-chat 467] Re: V1974 Cyg, CP Pup, V603 Aql & RW UMi progenitors

[Taichi Kato <tkato>]

Dear Dr. Retter,

> As for RW UMi, it is indeed about 2 mag. above its preoutburst
> level, but the nova decayed first to its 21st pre-discovery mag.,
> and the light was increased afterwards. (Howell et al. 1990, PASP,
> 102, 758), so it's probably a different case.

   According to the table caption of this Howell et al.'s paper, the
reference of the post-eruption magnitude should be Kularkin's IBVS 18.
However, there does not seem to be such; the POSS exposure was taken
only before the nova eruption.  There are several other good post-outburst
quiescence photometry of RW UMi: Cohen (ApJ 292, 90), and Kaluzny and
Chlebowski (Acta Astron. 39, 35), both of which give magnitudes of
18.5-19.  If RW UMi is indeed a below-the-period-gap object, what about
this in your calculation?  Using the observed amplitude (present-maximum)
of 12~13 mag and the absolute maximum magnitude of slow novae, the present
magnitude might seem to become critically close to the lower limit of an
thermally stable accretion disk.

> I wander whether anyone can comment on the progenitor of V603 Aql.
> Is it known? Is it below its mv=12 present state?

   Being abobe the period gap, I would not wonder if V603 Aql had the same
magnitude before and after the outburst.

Regards,
Taichi Kato

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