[vsnet-alert 25775] Re: V1405 Cas brightening

Taichi Kato tkato at kusastro.kyoto-u.ac.jp
Thu Apr 29 07:56:18 JST 2021


Taguchi-san,

> According to Munari et al. (ATel #14476), E(B-V)=0.55 is estimated.
> Also, assuming it and m_B - m_V = 0.4 from the AAVSO lightcurve, 
> extinction-free B - V will be -0.15.
>
> If it is true, the temperature is high and the bolometric correction for 
> V will be -1.2 or -1.3 from Pecaut & Mamajek (2013).

   Thank you for the estimate.  I have corrected to A(V)=1.7.
M(bol,premaximum) = -6.2.
Using Hachisu and Kato (2004), M(WD) = 1.27 Msolar.
This should be regarded as an upper limit since the relation
in Hachisu and Kato was for V.

   Their Fig. 1 suggests that the temperature is
much lower (<6000K) during the premaximum halt,
which is apparently in disagreement with
the present observation.  Please compare with V723 Cas,
which probably explains why V1405 Cas was initially
an He/N nova, and it is time to write a report or paper,
Taguchi-san!

   



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