De Stella Nova

De Stella Nova in Pede Serpentarii (On the New Star in the Foot of the Serpent Handler), generally known as De Stella Nova was a book written by Johannes Kepler between 1605 and 1606, when the book was published in Prague.

Kepler wrote the book following the appearance of the supernova SN 1604, also known as Kepler's Supernova. This star appeared in the constellation Ophiuchus, the Greek (Ὀφιοῦχος Ophioukhos) "serpent-bearer" which is also known in Latin as Serpentarius.

The SN 1604 supernova was observable for almost a year, from October 1604 to October 1605. Observation conditions were good, particularly when it was first visible. A conjunction of Jupiter and Mars happened to be taking place near the place where the supernova appeared, meaning that astronomers happened to be looking in its direction. As a result there were many witnesses to its appearance, but Kepler's observations were particularly meticulous. The care he took not only to record his own observations but to compile the observations of other astronomers make De Stella Nova a very important record both of the supernova itself, and of the astronomy of the early 17th century.