Charles-Eugène Delaunay

Charles-Eugène Delaunay
Charles-Eugène Delaunay
Born	April 9, 1816(1816-04-09) Lusigny-sur-Barse, France
Died	August 5, 1872(1872-08-05) (aged 56) Cherbourg
Nationality	French
Fields	astronomy
Institutions	Paris Observatory
Known for	lunar motion studies

Charles-Eugène Delaunay (April 9, 1816 – August 5, 1872) was a French astronomer and mathematician. His lunar motion studies were important in advancing both the theory of planetary motion and mathematics.

Life

Born in Lusigny-sur-Barse, France, Delaunay studied under Jean-Baptiste Biot at the Sorbonne. He worked on the mechanics of the Moon as a special case of the three-body problem. He published two volumes on the topic, each of 900 pages in length, in 1860 and 1867. The work hints at chaos in the system, and clearly demonstrates the problem of so-called "small denominators" in perturbation theory. His infinite series expression for finding the position of the Moon converged too slowly to be of practical use but was a catalyst in the development of functional analysis^[1] and computer algebra.^[2]

Delaunay became director of the Paris Observatory in 1870 but drowned in a boating accident near Cherbourg, France two years later.^[1]

Honours

• Member of the Académie des Sciences, (1855);^[3]
• Gold Medal of the Royal Astronomical Society, (1870).^{[citation needed]}
• His name is one of the 72 names inscribed on the Eiffel Tower.

References

1. ^ ^{a b} O'Connor & Edmund
2. ^ R. Pavelle, M. Rothstein and J. Fitch, "Computer Algebra", Scientific American, 245 (6), pp.102-113 (December 1981)
3. ^ [Anon.] (2001)

Persondata
Name	Delaunay, Charles-Eugene
Alternative names
Short description
Date of birth	April 9, 1816
Place of birth	Lusigny-sur-Barse, France
Date of death	August 5, 1872
Place of death	Cherbourg