[vsnet-chat 195] Re: V versus v Re to vsnet-chat 181

[Taichi Kato <tkato@kusastro.kyoto-u.ac.jp>]

Roland Boninsegna wrote in [vsnet-chat 193]:

>The discrepancies between v and V don't matter even for visual estimates of
>short
>period variable stars. A determination of the time of a minimum, made on an
>eclipsing star, from visual estimates, will be as valuable as a
>photoelectric one
>(especially if no photoelectric measures has been done!).

   It would be interesting in this thread to mention that period determination
algorithms based on Fourier transform is also little affected, even in merged
data, by systematic shifts from person to person, since constant offsets
give zero Fourier transform (for randomly sapmled data of enough time span).
I have once tried to reduce the scatter in the visual light curve of R CrB
stars by adding a constant shift value for each person.  The light curve
became pretty better (!), but I got a little disappointed to find the
resultant Fourier transform virtually remained unchanged.

   Period finding using dispersions (like PDM) will be more affected.

Regards,
Taichi Kato

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