1502: Regiomontanus

Regiomontanus

One of the most important astronomers from the second half of the fifteenth century was Johann Müller, born on 6 June 1436 in Königsberg, Bavaria. Müller was to acquire great fame under the name Regiomontanus, a latinization of his birthplace.

Life and career

Little is known about his youth. At the age of eleven he was enrolled at the University of Leipzig, and at fourteen he went to study at the University of Vienna, celebrated for its faculty of mathematics and astronomy. Georg von Peuerbach (1423-1461) had just been appointed professor there. Peuerbach was a student of the astronomer Johannes de Gamundia (c. 1380-1442), the compiler of the oldest known xylographic calendar from 1439. Peuerbach and Regiomantanus together made many important astronomical observations and worked on a new catalogue of constellations. In 1461 they were invited by Cardinal Bessarion to come to Rome. Here Regiomantanus was given the opportunity to delve more deeply into ancient Greek writings on mathematics and astronomy. After the death of Peuerbach, Regiomontanus was appointed professor in Vienna. In 1469, King Matthias Corvinus of Hungary invited him to come work at his court for a few years. That may not have been the most inspiring place for him, as two years later he left to go to Nuremberg. Here a wealthy merchant, Bernhard Walther, made it possible for him to build an observatory as well as a printing shop, so that for many years he was able to publish his now-famous ephemerides (astronomical tables).

Ephemerides

The first edition appeared in 1474 for the years 1475 through 1506 and included the astronomical length and width of the sun, the moon and the five planets as well as a table with the geographical coordinates of important sites on earth. Great explorers such as Columbus and Vasco da Gama made grateful use of his ephemerides.

Calendar reform

Owing to his reputation, Pope Sixtus IV asked his assistance in the impending calendar reform. In 1475 he was invited to come to Rome, but Regiomantanus appeared to have little interest in going. The pope even appointed him Bishop of Regensburg, a rather strange turn of events since he was not a member of the clerical order.

Death and posthumous reprints

In Rome he fell victim to the plague and died on 6 July 1476. Although Regiomantanus only lived to the age of forty, his influence has been vast. His almanacs served as a model for later astronomers and were reprinted long after his death, as can be seen with this 1502 edition from Zwolle.