[vsnet-chat 2852] Re: (fwd) TASS Variable Carbon Stars (Greaves)

[Taichi Kato <tkato>]

Re: [vsnet-chat 2849] (fwd) TASS Variable Carbon Stars (Greaves)

>      It is best when one does this sort of catalogue match-up to _not_rely_
> on the positions in the catalogues themselves unless they are more-or-less
> primaryu astrometric catalogues themselves.  The CGCS is a good example:
> plenty of the "accurate" positions there (those given to 0s.1/1" precision)
> are off by a lot, say 30" or more.  What's really required is to check on
> an image that the positions for all the candidates are correct and real.
> You can do this easily using the Goddard SkyView server, for instance, which
> allows a coordinate gird to be overlain on a DSS cutout.  Blind matching
> of catalogues is guaranteed to lead you astray.

   As already exemplified many times, our catalog cross-identifications
for new variable stars have been always made by eye examination of the
field on a graphic viewer and catalog positions.  CGCS is generally far
better than other general catalogs of certain classes of objects, but still
contains a number of inaccurate coordinates.

Regards,
Taichi Kato

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