This extremely slow but steady cycle of precession was discovered around 150 B.C by the ancient astronomer Hipparchos. Hipparchos combined the qualitative geometrical systems of the Greeks with the quantitative astronomy of the Babylonians, whose ancient observations were etched on cuneiform tablets. This remarkable fusion of cultures, embodied in the achievements of Hipparchos, greatly benefited Ptolemy 300 years later. From the constancy, order, symmetry and calm which are associated with the divine, astronomy makes its followers lovers of this divine beauty, accustoming them and reforming their natures, as it were, to a similar spiritual state. The size of each star indicates its relative magnitude .
Constellation names are light blue .
Messier object numbers are pink . Globular clusters are gold starbursts . Open clusters are dotted white circles. Planetary nebula are green diamonds . Bright nebula are magenta squares .