Associations between the ancient star catalogues (Q1862866)

By a careful statistical analysis of the star catalogue of the Almagest and of what is known of Hipparchus's catalogue (reduced to the same epoch), the author shows that it is most unlikely that Ptolemy's catalogue is independent of Hipparchus's (or of a common ancestor). He also notes that Pickering has detected some outliers in Hipparchus's data which seem to indicate that the latter used spherical trigonometry.