Petrus Apianus (April 16, 1495 – April 21, 1552; also known as Peter Apian) was a German humanist, famous for his works in mathematics, astronomy and cartography.
The Apianus crater on the Moon was named in his honour.

Life and work

Cosmographicus liber, Landshut 1524.
Ein newe und wolgegründete underweisung aller Kauffmanns Rechnung in dreyen Büchern, mit schönen Regeln und fragstücken begriffen, Ingolstadt 1527. A handbook of commercial arithmetic; depicted in the painting The Ambassadors by Hans Holbein the Younger.
Ein kurtzer bericht der Observation unnd urtels des jüngst erschinnen Cometen..., Ingolstadt 1532. On his comet observations.
Quadrans Apiani astronomicus, Ingolstadt 1532. On sextants.
Horoscopion Apiani..., Ingolstadt 1533. On sundials.
Instrument Buch..., Ingolstadt 1533. A scientific book on astronomical instruments in German.
Instrumentum primi mobilis, Nuremberg 1534. On trigonometry, contains sine tables.
Astronomicum Caesareum, Ingolstadt 1540.