Johann Wilhelm Andreas Pfaff

Johann Wilhelm Andreas Pfaff (5 December 1774 to 26 June 1835) was a German mathematician, physicist and astronomer, the youngest of twelve children of a Stuttgart finance official and the younger brother of the mathematician Johann Friedrich Pfaff. He studied philosophy and theology at the Tübingen seminary, travelled widely, and in 1803 became professor of applied mathematics and astronomy at the newly founded University of Dorpat, where he founded the observatory and worked on astrometry, precession and planetary perturbations. In 1809 he moved to the Realstudienanstalt in Nuremberg, then taught at Würzburg in 1817 and from 1818 held the chair of mathematics at Erlangen until his death. At Erlangen he directed the physical cabinet, lectured on astronomy, took an interest in spectroscopy and supported Joseph Fraunhofer. His attempt to rehabilitate astrology drew sharp criticism from Gauss, Bode and Olbers. He belonged to the academies of St Petersburg and Bavaria.