[vsnet-chat 2959] (fwd) Tycho,Tycho-2,Hipparcos magnitudes

[Taichi Kato <tkato>]

(fwd) Tycho,Tycho-2,Hipparcos magnitudes

   This note is from S. Otero, which would be of public interest.

From: Sebasti疣 Otero <varsao@fullzero.com.ar>

                Thank you very much for your answer. I'll send my
observations with TYCHO and TYCHO 2 magnitudes. I've been comparing both
catalogues and I found that , as you said, TYCHO 2 is better, but only in
the case of fainter stars and stars placed in crowded areas. For bright
stars (up to 7 or 8 mag.) , TYCHO magnitudes are better . TYCHO 2 magnitudes
of bright stars tend to be brighter than they are and the colour indexes
lower. But, since almost all the stars we estimate are not very bright,
TYCHO 2 is the better choice.
                 We don't have to forget the high accuracy of Hipparcos
measurements, so every time a star has a HIPPARCOS magnitude, this becomes
the better choice.

[...]

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