Urania's name attached itself to one of the most consequential works in the history of astronomical mapping: the Uranometria, a star atlas published in 1603 by the German lawyer and amateur astronomer Johann Bayer, whose title simply means the measuring of Urania, treating the Muse's name as a byword for the discipline of astronomy itself. Bayer's atlas was groundbreaking for its systematic depiction of the constellations, including, for the first time in a major published atlas, twelve new southern constellations invisible from Europe, recorded from observations made by Dutch navigators on voyages to the East Indies, extending Western star charts decisively into the southern sky for the first time. The Uranometria also introduced what became known as the Bayer designation system, assigning Greek letters to stars within each constellation roughly according to brightness, Alpha Centauri and Beta Orionis being familiar examples of a naming convention astronomers still use today, more than four centuries after Bayer devised it specifically for this one book.
Bayer's choice of title, honoring Urania as the Muse traditionally associated with the heavens and their study, situates a foundational work of early modern observational astronomy squarely within the older tradition of invoking a Muse to dignify a serious, systematic intellectual undertaking, the same impulse that led Milton and Du Bartas to invoke her name in verse around the same period. Where their invocations were poetic gestures, Bayer's was practical and technical, and it is his use of her name, attached to a working reference tool astronomers still cite by its Latin title, that arguably gave Urania her most durable and functionally useful afterlife of all.