[vsnet-newvar 715] Re: 'Q' numbers of 'The Astronomer'

[Taichi Kato <tkato>]

Re: 'Q' numbers of 'The Astronomer'

> Some may propose to use the GSC, USNO-A2.0, or IRAS numbers. But if a
> star are recorded in all of those catalogs, what number should we use?
> When the MISAO Project report a star using the GSC number and others
> report it using the IRAS number, it makes a confusion and
> inconvenience. In case not recorded in any catalogs, we cannot
> determine the name.

   I think there is no unique answer.  One should bear in mind IRAS catalogs
are far infrared catalogs with an positional accuracy of ~1 arcmin, which
can sometimes make unique optical indentifications difficult or impossible.
(The 2MASS catalog has already revealed incorrect identifications based on
IRAS presumable identifications only).

   When we made an arrangement of the VSOLJ database, we adopted a priority
of catalogs for "unnamed" stars: Beyer name > NSV > BD > CD > CPD > GSC >
others (at that time USNO catalogs didn't exist).  This followed the
convention in identifications in Name Lists.  Some stars were called by
their IRAS names or other names (including well-known old generation
catalogs like HD, SAO), mostly from literatures, but we didn't rigorously
convert them to the corresponding BD/CD/CPD or GSC names.

> Some may propose to use the R.A and Decl., like J123456.78+123456.7. 
> But when several people reported their own astrometry reports, which
> position should we use?

   As Yoshida-san has pointed out, the introduction of coordinate-based
system from multiple sources causes rounding or borderline problems, as
has been historically (notoriously) experienced in the Harvard number
system.  [Indeed we, other than the AAVSO special staff(?), have no concrete
way to convert coordinates to the permanent Harvard numbers...]

Regards,
Taichi Kato

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