Ephemerides

work by Regiomontanus

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June 26, 2026

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Regiomontanus, a prominent 15th-century mathematician and astronomer, created an influential work titled Ephemerides. Published in 1474, this book provided daily positions of celestial bodies, showcasing his advanced computational skills.1

An ephemeris is a table that lists the positions of celestial bodies over time. Regiomontanus's work was an early example of such a table and also introduced the principle of determining longitude using lunar distances. This method, though not practical for centuries, laid groundwork for future navigational advancements. Modern ephemerides are crucial for astronomers and navigators and are now calculated using powerful computers.23

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Almanacs and tables
…of the heavenly bodies was Ephemerides, compiled by the German astronomer Regiomontanus and published by him in Nürnberg in 1474. This work also set forth the principle of determining longitude by the method of lunar distances—that is, the angular displacement of the Moon from other celestial objects. This method, which…
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…of the heavenly bodies was Ephemerides, compiled by the German astronomer Regiomontanus and published by him in Nürnberg in 1474. This work also set forth the principle of determining longitude by the method of lunar distances—that is, the angular displacement of the Moon from other celestial objects. This method, which…
Read More

Regiomontanus
…Latin calendars, and his 896-page Ephemerides (daily planetary positions for 32 years, which showcase his computational skills). His editions pioneered the printing of astronomical diagrams and numerical tables. Several of the works that he prepared and had hoped to print, including editions of Euclid and Archimedes, his own astronomical Tabulae…
Read More
…Latin calendars, and his 896-page Ephemerides (daily planetary positions for 32 years, which showcase his computational skills). His editions pioneered the printing of astronomical diagrams and numerical tables. Several of the works that he prepared and had hoped to print, including editions of Euclid and Archimedes, his own astronomical Tabulae…
Read More