Astronomicum Caesareum

Artist: Michael Ostendorfer (German, (?) ca. 1490–1549 Regensburg)

Author: Petrus Apianus (German, active 1526–40) , German, 1495–1552

Printer: Georg and Petrus Apianus (German)

Date: May 1540

Medium: Hand-colored woodcuts

Dimensions: 17 7/8 × 12 11/16 × 1 5/16 in. (45.4 × 32.3 × 3.3 cm)

Classification: Books

Credit Line: Gift of Herbert N. Straus, 1925

Accession Number: 25.17


This most sumptuous of all Renaissance instructive manuals explained the use of the astrolabe (for calculating the altitude of stars) and other instruments used for computing planetary positions. The author, court astronomer to Emperor Charles V, also provided new observations on the comet of 1531 (Halley's Comet). Only about forty copies of this work survive; very few still have the seed pearls that were originally attached to the string markers on each of the eighteen disks.