Hi Stefano,

Sorry, I should have recognized what was going on here right away:
in the special case of UCAC-3 display, Guide assumes that it's getting
all the stars it needs from that catalog and that display of GSC and
Tycho-2 would just result in "software doubles".

Best I can suggest is that if you shut off UCAC-3 display temporarily,
then you'll get the GSC and Tycho stars back.

I did just realize that this has one bad side effect. If you have
UCAC-3 stars, then various labelling options (labelling stars by GSC,
Tycho, HD, common name, Bayer, etc.) are also shut off. In that
case, Guide should at least draw the GSC numbers, though not the
actual stars.

I can also imagine cases where one would want the old behavior, at
least temporarily, accepting as inevitable the sudden reappearance
of zillions of false doubles. I can make that a toggle. You wouldn't
want to do it very often, but it might happen.

-- Bill