[vsnet-gcvs 83] (fwd) [vsnet-chat 4361] Re: (fwd) re Tmz etc orthography

[Taichi Kato <tkato>]

From: crawl@zoom.co.uk
Date: Fri, 27 Apr 2001 10:43:50 +0000

Taichi Kato wrote:

>Very interesting.  I have't seen anything like M 001 or NGC 0205 :-)
>
>   John, should we use these M%03d or NGC%04d (in C format) nomenclature
>for the ease of future sorting?

You have a good point!  I've just been thinking about AC2000 1 for
instance, should I write AC2000 0000001 instead ;)

I think I'm thinking with respect to computers too much, the long AC2000
number would look very daft in published articles.

But we should look on the bright side, and for once be happy that the GCVS
and the like are not that well known for their positional accuracy
[especially for little known variables], or else we'd be refering to
variables as "GCVS 012345=B14321" [ie coordinates based naming], or the like
(yuck!!!!!).

The coordinate based naming systems may be useful and make sense for
mega-catalogues, but I can remember "V1436 Aql" without having to keep
double checking every 2 seconds!

Cheers

John

PS

Mati Morel wrote:

>Incidentally, I see that the GCVS uses three formats :
>V999 Sgr  in volumes 1-3; (no space)
>V 999 Sgr in vol. 4            (with space)
>V0999 ---  in vol. 5 & most recent namelist

Well here's one I noticed a while ago whilst cross thingying a bunch of
varied data (and using memory, without double checking): namely that the
GSC, Tycho1, Tycho2, AC2000, NSV supplement cross ID files and Brian
Skiff's LONEOS archive carry _six_ different formats for writing the same
GSC identifier!!!!

There are various characters used to delimit between the two numbers within
these catalogues, from spaces, to "-" symbol to ":" in some cases.  The
"padding argument" comes in here too... ...some say [for made up eg] GSC
1234 1, others GSC 1234     1, and others GSC 1234 0001 and yet others GSC
1234 00001 (I'm ignoring the Tycho only "3rd identifier").

This latter is an example of that other argument Chris Lloyd mentioned re
padded zeroes too, in this case when you go from 1000 to 10000.  For
instance, Brian uses GSC 1234-0001 format, whilst Tycho2 would call that
GSC 1234 00001.  Fair enough, few zones actually go over 9999 objects, so
it is a redundant practice a lot of the time, and obviously the 5 digit
situation hasn't cropped up for Brian yet.  On the other hand, when I was
matching up data from Brian's list against Tycho2 objects to check the
photometry quality of the latter I spent as much time fiddling with text
editors and macros and what have you to get all the name formats the same
for linking as I did actually getting on with processing the magnitudes and
graphing it! I went on then to check against Tycho1 so I could tally how
many of these stars were new to Tycho2 only to find the GSC formatting used
had been changed between Tycho1 and Tycho2...aaargh!  [Fortunately I had
sense to change the formats in Brian's file rather than those in Tycho2,
which is a bit bigger ;) ...]

[NB this is in no way a criticism of anybody's catalogue and/or data
lists!!!!  Just saying is all.  It'd be better if groups would take more
time in thinking up what codes they want to use, making use of the proper
rules, and asking advice from the CDS people who keep a big dictionary on
this sort of thing, and who also have a bit of experience in it (mainly
through reverse engineering old catalogues).  Although this statement seems
self-evident, the point is that it always seems to happen that if naming
rules aren't laid down in the first place everybody who subsequently uses
the catalogue will each make up their own version!  Here I've given the GSC
as prime example]

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