Philippe Gustave Doulcet

Philippe Gustave Doulcet, Comte de Pontécoulant (1795–1874) was a French astronomer.

He was the younger son of Louis Gustave le Doulcet, Comte de Pontécoulant and was the brother of Louis-Adolphe Pontécoulant. After 1811 he served in the army until 1849. Following his retirement he dedicated himself to the study of mathematics and astronomy.

In 1829 he used the mathematical methods of Poisson and Lagrange to successfully predict the return of Halley's comet with good precision. His prediction of the perihelion passage was correct to within two days.

He was a member of the French Academy of Sciences. The crater Pontécoulant on the Moon is named after him.

...
Wikipedia