Bellow installation procedure uses only command line approach, because this is the simpler way to follow instructions just by copy-pasting the commands in terminal. Instructions tested on Ubuntu 11.10 and Ubuntu 11.04.
sudo apt-add-repository 'deb http://www.ap-i.net/apt stable main'
Note: If you would like to install development version of Skychart instead of stable version, then replace word “stable” with “unstable” in above and bellow commands.
sudo apt-add-repository --remove 'deb-src http://www.ap-i.net/apt stable main'
gpg --keyserver keyserver.ubuntu.com --recv C56CCB02D79BF92A
gpg --export --armor C56CCB02D79BF92A | sudo apt-key add -
sudo apt-get update
sudo apt-get install --no-install-recommends skychart
sudo apt-get install skychart-data-stars skychart-data-dso skychart-data-pictures
LIBOVERLAY_SCROLLBAR=0 skychart
Note: LIBOVERLAY_SCROLLBAR=0 option turns off Unity overlay scroolbars for this particular program, because there is some bug in the code preventing Skychart to start correctly if this overlay scrollbar is turned on.