[vsnet-chat 1922] Re: Perplexing questions, UV delay?

[Noah McBurnett <stardude@bellsouth.net>]

My Name is Noah McBurnett and i find this uv delay very interesting I have not
really encountered this.  Is this due to the mass being accreted onto the white
dwarfs surface and could this pose as a something to hit us to the trigger?
this seems to me as to support the viscosity instability theories.  Is this
so?  and may it also be looked at as it takes time for the mass to spiral from
the hot spot once it is formed causing the dely of higher energies i.e. UV from
the potential energy being released from the matter as it slams into the
surface of the WD.  These are just things i am seeing from this i have heard of
this but at the time not in depth is there any literature i may find?

Clear Skies
Noah McBurnett

Taichi Kato wrote:

> Re: [vsnet-chat 1882] Re: Perplexing questions, UV delay?
>
> Dear Justin,
>
> > in your reply, you made reference to ( UV time delay
> >  between simultaneous satellite and visual observations). Forgive
> >  me if I make a few assumptions, but I presume the time delay is
> >  to visual observers, and the delay of the UV component somehow
> >  effects our visual observations?
> >  If so, is our atmosphere the mechanism that causes time
> >  delay?
>
>     UV-delay in dwarf novae: even more preplexing, dwarf nova outbursts
> occur in the visual light earlier than in the UV light.  Usually one day
> after our familiar visual rise (e.g. VW Hyi), the UV light starts to rise.
> This it not caused by our atmosphere, but intrinsic to these stars.
>
>     This has been one of the central questions about the outburst mechanism
> of dwarf novae.  Successful outburst models must reproduce this time delay.
>
> Regards,
> Taichi Kato

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