Uranometria is a star atlas produced by Johann Bayer. It was published in Augsburg in 1603 by Christoph Mang (Christophorus Mangus) under the full title Uranometria: omnium asterismorum continens schemata, nova methodo delineata, aereis laminis expressa. This translates to "Uranometria, containing charts of all the constellations, drawn by a new method and engraved on copper plates". The word "Uranometria" derives from Urania, muse of the heavens and "uranos" (oυρανός) the Greek word for sky / heavens. A literal translation of "Uranometria" is "Measuring the Heavens" (to be compared with "Geometry"—"Geometria" in Greek, literally translated to "Measuring the Earth"). It was the first atlas to cover the entire celestial sphere. Charts Uranometria contained 51 star charts, engraved on copper plates by Alexander Mair ( 1562–1617). The first 48 charts illustrate each of the 48 Ptolemaic constellations. The 49th chart introduces 12 new constellations in the deep southern sky, which was unknown to Ptolemy. The final two charts are planispheres labeled "Synopsis coeli superioris borea" and "Synopsis coeli inferioris austrina", or (roughly), "Overview of the northern hemisphere" and "Overview of the southern hemisphere". Each plate includes a grid for accurately determining the position of each star to fractions of a degree. The positions used by Bayer to create the Uranometria were taken from the expanded 1,005-star catalog of Tycho Brahe. Brahe's expanded list had circulated in manuscript since 1598 and was available in graphic form on the celestial globes of Petrus Plancius, Hondius, and Willem Blaeu. It was first published in tabular form in Johannes Kepler's Rudolphine Tables of 1627. Uranometria introduced the convention of labelling stars by Greek and Latin letters, known as Bayer designations, a system still in use today. The use of Brahe's catalog allowed for considerably better accuracy than Ptolemy's somewhat limited star listing. The stars listed in Uranometria total over 1,200, indicating that Brahe's catalog was not the only source of information used. Bayer took the southern star positions and constellation names for the 49th plate from the catalog of Dutch navigator Pieter Dirkszoon Keyser, who corrected the older observations of Amerigo Vespucci and Andrea Corsali, as well as the report of Pedro de Medina. Uranometria contains many more stars than did any previous star atlas, though the exact number is disputed as not all stars on the charts are labeled. The stars of each constellation are shown overlain on an engraved image of the subject of