[vsnet-chat 1284] Re: [vsnet-obs 14762] Re: V3885 Sgr, this season

[Taichi Kato <tkato>]

Re: [vsnet-obs 14762] Re: V3885 Sgr, this season

Berto Monard wrote:

> V3885 Sgr is a novalike cv with high accretion flow. This makes it a
> very blue object.
> The shown visual estimates may be a point in case for the blue light
> attenuation experienced in Japan, as pointed out by Dr T Kato or is
> this a case of different sequences??
> I used H/T!

   I have confirmed T. Watanabe also used H/T.  So this systematic difference
may be attributed to personal perception to the blue light.  Two possible
reasons:

   1. Japanese sky is polluted enough to discourage CV observers (;_;)

      (However, T. Watanabe usually observes from Mt. Fuji, the highest
       mountain in Japan, but slightly lower than Mauna Kea, this effect
       might be then avoided, or the air pollution already prevailing all
       heights of atmosphere?)

   2. Dark adaptation, but I presume he is reasonably dark adapted in the
      dark environment of the mountain.

   Considering the typical color of B-V=0 for these bright novalikes, there
will not be a large difference in color term by the effect (2).  However,
the situation will be different if Monard's eye has a sensitivity to the U
light!  CVs are bluer than OB stars in the U-B index.

   How do you think?

Regards,
Taichi Kato

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