Fine example of Johann Bayer's map of the constellation Auriga, with stars heightened in Gold and manuscript annotations noting neighboring constellations and the names of stars.
Auriga is a constellation in the northern sky. Its name is Latin for 'charioteer' and its stars form a shape that has been associated with the pointed helmet of a charioteer. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and is included among the 88 modern constellations. Its brightest star is Capella.
Perhaps the most important of all celestial atlases is Bayer's Uranometria, the forerunner of all star atlases which contained 51 star charts, of which 48 were Ptolemaic constellations. Each plate has a carefully engraved grid, so that star positions can be read off to fractions of a degree. These positions were taken, from the catalog of Tycho Brahe, which had circulated in manuscript in the 1590s, but which was only printed in 1602.
Another important feature of the atlas was the introduction of a new system of stellar nomenclature. Bayer assigned Greek letters to the brighter stars, generally in the order of magnitude, so that the bright star in the Bull's eye became alpha Tauri (and the brightest star in the Centaur became our familiar alpha Centauri.) These letters were placed on the charts themselves, and also in a table that accompanied each chart. Bayer's charts are rarely offered separately on the market.