[vsnet-chat 3643] Re: Overobserving

[Taichi Kato <tkato>]

Re: [vsnet-chat 3641] Re: Overobserving

> I note Taichi Kato's comments about Mira itself. The VSOLJ is not the only
> organisation where this star is measured by hundreds of observers. The
> resulting light curve is almost unusable.

    I wonder whether analysts apply corrections for systematic differences
between observers.  My experience with the VSOLJ data has quite contrary
impression.  After correcting systematic differences (by an analytic way),
the resultant light curve is often far better than a combination of
a selected prolific observers with less frequent observations.
Even low-amplitude multiperiodic light modulations in R CrB stars can
be detectable (R CrB itself has a far less amplitude than that of RY Sgr
or V854 Cen), using an ensemble of densely sampled (ideally one per night
for each observer) data.

> In reality it's the CVs that are overobserved by visual
> observers. Not during quiescence but during outbursts. The moment a star is
> bright everone and his dog is measuring it six times a night. There are
> well-known features during outbursts but it's useless to try to document
> these visually.

    Not all CV outbursts are recorded by PEP or CCD.  Actually only few of
them are observed in sufficient manner.  [Even in the presence of early
warnings of BF Ara outbursts, I have not yet heard of CCD/PEP observations
which are sufficient to conclude that dense observations are no longer
necessary.]  Every CV outburst may have its own variety, as best experienced
in the well-known SS Cyg or U Gem, in some of whose outbursts "dips" were
observed during outbursts.  Unfortunately there were NO simultaneous
CCD/PEP observations, and analysts have had to rely on visual observations.
I wonder whether this is already the feature overdocumented using CCD/PEP
observations.

Regards,
Taichi Kato

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