[vsnet-chat 1874] Re: Perplexing questions?

[Taichi Kato <tkato>]

Re: [vsnet-chat 1873] Perplexing questions?

Dear Justin,

> I would like to know how they are used against
> professional observations, to produce information about
> a particular star?

   Quite an interesting and important question.  Long-term visual light
curves have been most frequently used in what is called correlation analysis.
This analysis is done by correlating a visual light curve with other
variability information (X-ray variability, gamma-ray detection, radio,
optical spectrum and photometry in other wavelength etc.).  This makes
one of the most important contributions to professional astronomy.
Best examples include the discovery of the UV-delay in simultaneous
visual and satellite observations of dwarf novae, intraday variablity of
blazars -- possible time delay between visual and gamma-ray variability
and many others amateur observations are referred to, included, or even
make the most inportant part of the paper.

   Visual observations in themselves can be worth analyzing, using various
mathematical techniques.  A survey of period changes in pulsating stars
led to the discovery of the helium shell-flash effect, chaos has been
searched in the long-term light curve of dwarf novae, and again many
others.

   And still the most important role amateur observing has been playing
is the early notification of rare or unique phenomena, in dwarf novae and
other peculiar variable stars, discovery of novae and SNe.  Without
them, the mechanism of dwarf nova outburst may have largely delayed.

> For example (V4444 Sgr) do professionals observe this
> star using some part of the (electromagnetic spectrum),
> or just some part of the (visual light spectrum)?
> If so how do our visual observations, directly relate to
> either, and what information does this give us?

   I think it may be too limited to explain what information can be
obtained in novae by combinations of visual and other modalities.  This is
a very wide field.  Even the nova theoretical light curve is difficult to
repreduce very recently; now it's established the combination of visual
and UV light curves can constrain the mass of the white dwarf.  M. Kato
used many visual observation appearing in IAUCs (the scatter having been
often the cause of complaints), but now we can provide visual observations
on the unprecedentedly systematic scale, thanks to all efforts to Henden,
Skiff and Sumner.  This is an only one example of renowned outcomes from
coordinated mutiwavelength nova observations.

Regards,
Taichi Kato

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