[Kstars-devel] Re: Poor quality of data in kstars main catalog?

[Massimiliano "Max Negro" Masserelli]

Il giorno dom, 10/04/2011 alle 12.12 -0500, Akarsh Simha ha scritto:

> Most of our star data comes from Tycho-2 and USNO NOMAD. So that means
> that we got the epoch wrong? So what we thought are J2000.0 data are
> actually J1991.25 data?

If I understand correctly Tycho-2 and USNO NOMAD are used only for star
fainter than 8.0 (it's hard to verify, since at least tycho2 is in
binary format). What I'm talking about here is the "main" catalog, the
one in stars.dat. From what I can see, this one is based on Hipparcos
(with custom modifications such as star names). Hipparcos has
coordinates expressed in J1991.25 as clearly stated in the README
available at the url specified as data source in stars.dat
(http://cdsarc.u-strasbg.fr/viz-bin/Cat?I/239)

> Deep Sky Objects are in general inaccurate in KStars. Do you have any
> suggestions for a standard Deep Sky catalog that is accurate and free
> (as in distributable under terms of the GNU General Public License)?

Sadly, I'm not an astronomer so I'm not very informed on the subject. If
I happen to have some hints I'll let you know. I can see Yale catalog
and Gliese catalog are available as debian packages (yale is in
non-free) but none of them has coordinates for deep sky objects.

> We are allowed to redistribute the Saguaro Astronomy Club's database,
> which is an amateur-compiled database with a lot of observational
> details etc. I plan to merge our NGC / IC database with the broader
> and more accurate SAC database.

Any plans on integrating those data (and others) with stardata-common
"interface"?
-- 
Massimiliano "Max Negro" Masserelli <negro at interim.it>