April 30: Johann Karl Burckhardt

Johann Karl Burckhardt

April 30, 1773 – June 22, 1825

Johann Burckhardt was a German-born astronomer and mathematician who later became a naturalized French citizen.

Burckhardt was born in Leipzig where he studied mathematics and astronomy. Later he became an assistant at the Gotha Observatory and studied under Franz Xaver von Zach. On von Zach's recommendation he joined the Paris Observatory, then directed by Jérôme Lalande. Burckhardt focused his studies on the orbits of comets. He joined the Bureau des Longitudes in 1795. In 1799, he became a naturalized French citizen. He was elected to the L'Institut National des Sciences et des Arts in 1804. After Lalande died in 1807, Burckhardt succeeded him as director of the Paris Observatory.

Between 1812 and 1825, he published Tables de la Lune, based on a lunar theory distinct from that of Pierre-Simon Laplace. Burckhardt's lunar tables enjoyed a substantial reputation for a time, and they were officially used for computing the lunar ephemeris in the Nautical Almanac from 1821 to 1861 (superseded in part, as from 1856, for the lunar horizontal parallax, by tables due to J C Adams, and eventually replaced altogether, for issues from 1862, by the tables based on P A Hansen's more comprehensive lunar theory).

The Lunar crater Burckhardt is named in his honor.