[Kstars-devel] Catalog artefacts in USNO NOMAD

[Akarsh Simha]

The attached file seems to be a good example of many artefacts in USNO
NOMAD, which AFAIK has been generated automatically by analyzing
images. Here are some consistent cases that I've noticed:

1. There is a star at the core of every galaxy (easy to filter out)

2. Sometimes, diffraction spikes around bright stars are turned into a
chain of stars!

3. Sometimes, bright single stars are turned into double stars (must
be another diffraction-spike effect)

4. Faint companion stars of bright stars tend to be exaggerated in brightness.

5. The star clouds of the milky way have resulted in huge patches of
stars as artefacts.

Most of the other issues are hard to debug from the catalog. I'm sure
there is a better catalog? Can we move to it? Stellarium has a 600
million star catalog, AFAIK? Is it free from such artefacts?

Regards
Akarsh
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