Hi Alfredo,

There are a lot of different options here.

Guide 9 uses UCAC3 for its star maps, much as Guides 1 through 8
used GSC.

You can get Guide 8 or 9 to display UCAC4. To do so, you will need
the UCAC4 disks, and the very latest Guide 8 or 9 software.

http://www.projectpluto.com/new.htm

...which also has instructions on how to get UCAC4 to appear. (Which
does seem to be giving people trouble. I plan on clarifying the
instructions a bit.)

You can also upgrade to Guide 9, if you wish. The new version is
described a bit at

http://www.projectpluto.com/guide9.htm

If you just want to go ahead and order, try this page:

http://www.projectpluto.com/guide9a.htm

The next problem is getting a copy of UCAC4. USNO distributes it on
a double-sided DVD. (The data comes to about 8 GBytes.) Copies have been
slow in coming. Send me your mailing address, and I can get a copy to
you at no charge; however, after you have copied the disks, I will ask
you to mail them to somebody else.

-- Bill