[vsnet-chat 460] Re: V1974 Cyg Campaign - critical value - answer to Taichi Kato

[Taichi Kato <tkato>]

Dear Dr. Retter,

   Thank you very much for your explanation.  I now understand very well.
It looks like better to wait for your paper to come out before further
discussing how and why the mass-transfer rate varies after the nova
eruption, but I have some questions regarding the prenova.

> For Nova Cygni, at about Mv=16 now-days, we got a
> range of 17.5-18.5, which is well above its 19.5 pre-outburst
> brightness.

   I believe this value is from Annuk et al. (A&A 269, L5, 1993), but
it seems to me a bit queer they did not mention the 18-mag star (the star
Skiff initially reported as the progenitor) 2 arcsec from the nova position,
and their claim of the clear appearance on POSS plates seems to contradict
with the earlier failure in detecting the prenova.  I wonder how this
discrepancy has been solved, and what was the true prenova -- though your
suggestion would not be changed even the prenova was fainter than mv=20.

   I remember I have once read CP Pup was undetected on preoutburst plate(s).
I would also like to know the current understanding of the prenova state
of this nova.

> We are writing a letter to the MNRAS on this subject. It will probably
> be prepared in a week or so. I'll mail it to the vsnet as soon as it is
> ready.

   Eagerly looking for it!

Regards,
Taichi Kato

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