Born Jan. 13, 1845, in Nuits-Saint-Georges, Côte-d’Or Department; died Oct. 20, 1896, in Paris. French astronomer. Member of the Académie des Sciences (1878).
Tisserand graduated from the Ecole Normale Supérieure in 1866. In 1873 he became a professor in the faculty of sciences, and director of the observatory, at Toulouse. Between 1878 and 1892 he was a member of the Bureau of Longitudes and a professor at the University of Paris. In 1892 he became director of the Paris Observatory.
Tisserand’s works dealt mainly with celestial mechanics. He carried out a study of long-period planetary perturbations and concluded that such perturbations could not disrupt the stability of the solar system. He developed a test for determining whether a newly discovered comet is identical to a previously discovered comet. Tisserand founded the Bulletin astronomique in 1884 and edited it until his death.