The program now displays objects from the OpenNGC catalog (https://github.com/mattiaverga/OpenNGC) whose positions and data are much more reliable than those contained in the old SAC catalog.
This catalog was built using several sources: NASA/IPAC Extragalactic Database, HyperLEDA, Simbad, and HEASARC. It contains around 15,000 objects.
You can find details about its creation here: https://github.com/mattiaverga/OpenNGC/blob/master/README.md