science · 09 April 1816 · 208 years ago
birth
Born 9 Apr 1816; died 5 Aug 1872 at age 56.
French mathematician and astronomer whose theory of lunar motion advanced the development of planetary-motion theories. After 20 years of work, he published two volumes on lunar theory, La Théorie du mouvement de la lune (1860,1867). This is an important case of the three body problem. Delaunay found the longitude, latitude and parallax of the Moon as infinite series. These gave results correct to 1 second of arc but were not too practical as the series converged slowly. However this work was important in the beginnings of functional analysis. Delaunay succeeded Le Verrier as director of the Paris Observatory in 1870 but two years later he and three companions drowned in a boating accident.
OnThisDay.net