Susanne M. Hoffmann reconstructed the not preserved celestial globe (and star catalogue) of ancient Hipparchus of Nicaea digitally. She investigated the data (celestial coordinates) on this globe and traced their sources. By means of error analysis, visualizing, mapping, and correlation plots she examined the potential origin of the Hipparchian star coordinates (or some of them) in observations of earlier Greek or Babylonian data. As preserved by Ptolemy (Almagest) and Pliny the Elder, Hipparchus is famous for his exact observations but he does, of course, also rely on older data - e.g. especially elaborated by Ptolemy's discussion of precession.