Narratio Prima

De libris revolutionum Copernici narratio prima, usually referred to as Narratio Prima (Latin: First Account), is an abstract of Nicolaus Copernicus' heliocentric theory, written by Georg Joachim Rheticus in 1540. It is an introduction to Copernicus's major work, De revolutionibus orbium coelestium, published in 1543, largely due to Rheticus's instigation. Narratio Prima is the first printed publication of Copernicus's theory.

Copernicus, born in 1473 and already well over 60 years old, had never published any astronomical work, as his only publication had been his translation of poems of Theophylact Simocatta, printed in 1509 by Johann Haller. At the same time, he had distributed his ideas among friends, with manuscripts called Commentariolus. In the 1530s, he was urged to publish by many, yet still hesitated when in 1539, Rheticus arrived in Frauenburg (Frombork) to become Copernicus' first and only pupil. Philipp Melanchthon had arranged for Rheticus to visit several astronomers and study with them.

In September 1539 Rheticus went to Danzig (Gdańsk) to visit the mayor who gave Rheticus some financial assistance to publish the Narratio Prima. This Narratio Prima, published by Franz Rhode in Danzig in 1540, is still considered to be the best introduction to Copernicus' De revolutionibus orbium coelestium. As the full title states, the Narratio was published as an open letter to Johannes Schöner of Nuremberg (Nürnberg). It was bundled together with the Encomium Prussiae which praised the spirit of humanism in Prussia.

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