A page of Ptolemy's star catalogue. This is from a 1515 Venice publication, but the catalogue goes back to Ptolemy in the 2nd century BC and the stars were mainly drawn from older catalogues, but Ptolemy probably made some observations himself. The Renaisance star maps are based on catalogue positions. Credit: Claudius Ptolemy (Almagest, original edition: Alexandria, 2nd century; this image from a Venice 1515 publication); modern credit Linda Hall Library; more information.