[vsnet-chat 5775] Re: [AAVSO-DIS] survey, pixy etc

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

Re: [vsnet-chat 5773] Re: [AAVSO-DIS] survey, pixy etc

>>>  preferably use the code "Rc" instead of less informative
>>>  "R", when the observations are done with Kron-Cousins R system.  This is
>>>  to avoid a confusion with Johnson R system.
>
>     Is anyone anywhere using the Johnson R,I system?  What standards are
> available?  Did Johnson ever publish his RI standard stars?  The system
> has been disbanded for 20 years!

   Several people around me is still using Johnson R system (at least they
try to reduce their data on this system).  Although I am not aware of the
existence of Johnson RI standard stars having comparable precisions to
those of Kron-Cousins system, there is a widely available written definition
of the system prescription and a reasonable passband definition.
More practically, there is plenty of evidence of confusion between
Johnson R and Kron-Cousins R, as is already evident from compilations from
IAU Circulars.  Scuh a confusion can be reasonably avoid only if small
attention is paid to avoid simple "R" reports.  If one feels a need
to discriminate K and Ks (or K'), the discrimination between Rj and Rc
is a matter of comparable significance.

Regards,
Taichi Kato

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