Novæ ephemerides coelestium motum annorum 40. incipientes anno domini 1581. usq; ad annum1620: secundum . . . Nicolai Copernici hypotheses, prutenicasq[ue] Reinoldi tabulas accuratissime supputat, atq[ue] Gregorian correctioni Romani Kalendarij accommodat . . . ad inclitæ urbis Venetiarum longitudinem

Venice: Damianum Zenarium, 1582. Printers device on title-page and on last verso leaf of colophon. Woodcut borders and charts, text illustrations, diagrams and tables throughout. Each year has a separate title as well as pages dealing variously with the calculations of the movements of celestial bodies, planetary positions, solar and lunar eclipses, festivals, annual revolutions, fixed stars, and much more. Contemporary vellum; text browned with some sections waterstained, still generally, a very good copy from the library of Owen Gingerich with his bookplate. First edition of the Novae ephemerides, the second part of Magini's famous tables to 1620, his first published work containing the rare first ephemerides for the new Gregorian calendar. The first part (Ephemerides coelestium motuum), published the same year, only covered the years through 1600.

In 1588 Magini (1555-1617) was chosen over Galileo to occupy the chair of mathematics at the University of Bologna after the death of Egnatio Danti. He was an outstanding astronomer and a correspondent of Tycho Brahe and Kepler. Indeed, Kepler, who referred to Magini as "summus in professione mathematica vir," invited him to help in the compilation of new astronomical tables (afterwards known as the Rudophine Tables). He made a thorough study of the writings of Copernicus, whose calculations of the celestial movements he considered far more exact than those of his predecessors. However, he defended the Ptolemaic system of astronomy, despite the fact that he did incorporate Copernicus' improvements of planetary theory in this work. Here, Magini insists on much larger diameters for the planets and fixed stars, providing actual figures and calculations. He devised his own planetary theory, in preference to other existing ones. Magini's notions about cosmic sizes were too eccentric to be influential. Yet, they have historical importance because Galileo used them to demonstrate the absurdity of pre-telescopic measurements of sizes of planets and fixed stars. Most historians surmise that Magini's rejection of the Copernican system was based on his fear of the inquisition.

The lunar crater "Maginusis" was named after him.