[vsnet-chat 2976] (fwd) Tycho magnitudes [for CHAT] (Greaves)

[Taichi Kato <tkato>]

(fwd) Tycho magnitudes [for CHAT] (Greaves)

Date: Sat, 27 May 2000 19:37:56 +0000
From: JG <jgts@jgws.totalserve.co.uk>
Subject: Tycho magnitudes [for CHAT]

Dear variable star observers

As far as I can tell, the biggest problem with magnitudes in Tycho1 or
Tycho2 is that folk constantly can't be bothered to use the plethora of
flags the Tycho teams included in the catalogues to first check whether the
proposed comparison star has any problems.

Tycho1 is full of such flags.  Tycho2 has fewer, but still includes
appropriate flags, and each Tycho2 star that is also a Tycho1 star is
flagged with a T in Tycho2.

As Erik H{/o}g et al point out in the intro to Tycho2, all such stars
should *also* have their data in Tycho1 checked re flags appropriate to
astrometry, photometry, etc... ...afore any use is made of the data.


...as for the plethora of variable star catalogues/surveys nowadays.  It is
fairly forgiveable for folk to fail to do literature searches etc if they
are just finding odd ones or twos of variables, possibly by accident,
especially if variables are not their main interest.

However, if professionals are running around making sizeable surveys with
the intent of publishing data on variability in stars, it is somewhat
remiss, if not just plain naughty, of them not to do the proper homework
and tally their results against the extant literature/catalogues.

If I went out next week and "discovered" a new variable which was first
noted in *their* surveys, and called it "Jonno 1", they'd soon jump up and
down squawking...

Cheers

John

John Greaves
UK

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