Hi Ben,

There are apt to be issues there...

With GSC, I built up a special index of "GSC stars within a few arcseconds
of NGC objects and PGC galaxies". That was good enough to clobber most of the
blatant problem cases. Then I put together a text file listing other GSC
stars that should be suppressed (some were asteroids, or plate defects, or
high proper motion stars that got recorded at two different places).

There's nothing like that for UCAC3. It's not as badly needed, since
UCAC3 starts out as a much "cleaner" dataset. But as you've noticed, it
does have some problems, and I may have to make an errata list, just as
I did for GSC.

> One other question. Why are all of the dimmer 3UCAC stars plotted in a>
> yellow to orange color? In a dense field displaying down to 15-17th mag
> stars, the display takes on a yellow-orange overall color because of the
> many 3UCAC stars being plotted. No big problem, but it just 'doesn't look right'.

The UCAC3 coloring is based on 2MASS infrared colors; there's a rough
transformation to get from the infrared J-K color to something approximating
"visual" color on-screen. As you've noticed, a lot of the fainter stars
are yellow-orange down to red. I think that reflects reality. You can
go into the Star Display dialog and either turn off colored stars, or
reduce the "saturation" level.

-- Bill