[vsnet-chat 718] Some more on charts and sequences again

[Taichi Kato <tkato>]

Robert Fidrich wrote:

> Since the use of different chart/sequence is the main cause of scatter in
> many cases, for the stars already have AAVSO sequences, we should prefer
> them until final standards to avoide scatter caused by different based
> sequences. 
> 
> For NEW stars (I mean stras without AAVSO or other sequences earlier) we
> can use HIP or Tycho V magnitudes for preliminary use, but we need to
> convert them to mv as soon as possibble.

   I think it would be a good option, even for immediate observations, to
adopt B-V selected V-mag sequence (from H/T and other available, reliable
sources).  Observations using this "standard" will not need to be modified
significantly (unless one tries to correct each eye's response ...) whatever
future standard might be.  I think you may start using these V-mag standard
even for well-observed stars (even like Mira, U Mon etc.), under specification
of the chart source as "V mag".  The observations that eventually need to
be adjusted are not thse V-based observations, but observations based on old
sequences.  There is no need to contine piling up these "need-to-be-corrected"
observations pending any organization's additional (and difficult) works,
when apparently better, universal, sequences are available.

Regards,
Taichi Kato

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