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

[keerthi kiran]

Hi all,
I am new to this group. But reading this post I wonder
what catalogs Stellarium and Cartes use. Cant we use the same catalogs? They
must be available under GPL right?

Regards,
Keerthi.

On Sun, Apr 10, 2011 at 11:10 PM, Victor Carbune
<victor.carbune at gmail.com>wrote:

> Hi there,
>
> On Sun, Apr 10, 2011 at 8:12 PM, Akarsh Simha <akarshsimha at gmail.com>
> wrote:
> > On Sun, Apr 10, 2011 at 02:28:34PM +0200, Massimiliano "Max Negro"
> Masserelli wrote:
> >> I'm in the process of introducing kstars to a local observatory for
> >> telescope control. While testing accuracy, I found some problems in
> >> pointing (with a 2000mm reflector with 40cm mirror). So I started
> >> looking at coordinates stored in catalog, and found "many" errors.
> >>
> >> In particular, Arcturus (alp Boo) has RA 14 15 40.35 Dec 19 11 14.17
> >> J2000. If you have a look at simbad
> >> (
> http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=arcturus&submit=SIMBAD+search) you'll see it should have RA 14 15 39.6720 Dec +19 10 56.677. I then
> looked at Hipparcos via Vizier (
> http://vizier.u-strasbg.fr/viz-bin/VizieR-S?HIP%2069673) and found that it
> shows the same coords as kstars, only in J1991.25 epoch (last batch of data
> on page, as follows):
> >>
> >> ...
> >> RAhms 14 15 40.35             Right ascension in h m s, ICRS (J1991.25)
> (H3)
> >> (pos.eq.ra;meta.main)
> >> DEdms +19 11 14.2             Declination in deg ' ", ICRS (J1991.25)
> (H4)
> >> (pos.eq.dec;meta.main)
> >
> > 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?
> >
> > This should not be very hard to fix once I get the star catalogs back
> > on my database.
> >
> >> I tried with a few other objects, and many were in the same conditions,
> >> save a few (Albireo, at least, as you can see in
> >> http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=albireo&submit=SIMBAD
> >> +search ).
> >
> >> Deep sky objects seems inaccurate, too, but I wasn't able to find an
> >> hint on why...
> >
> > 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)?
> >
> > 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.
> >
> > If you have something more accurate than SAC, that would be great.
> I'm working right now on moving our current deep data to a database
> using sqlite. I'd be glad to know suggestions about deep sky catalogs.
>
> Are there any other parts in KStars where deep sky objects are stored,
> aside from the ngic.dat?
>
> While doing this port, I just need to mention that we don't really
> have a proper parser, independent of kstars of that ngcic.dat file and
> the best method seems to just make KStars generate SQL insert queries
> while loading it. I spent quite a time trying to port the code to a
> generic parser in tools, but KSFileReader seems to include kstars.h
> and other things.
>
> So, here's my question, so I don't work on this in vain: if I just
> port all the data from ngcic.dat in a database, is there any reason
> why we would ever need that file again?
>
> Victor
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