Achille Pierre Dionis du Séjour
Encyclopedia
Achille Pierre Dionis du Séjour (January 11, 1734 – August 22, 1794) was a French
astronomer
and mathematician
.
Dionis du Séjour was born in Paris
and was a distant relative of surgeon and anatomist Pierre Dionis. He served as an advisor to parliament before he was appointed to the French Academy of Sciences
in 1765. He was appointed to the Paris group for the Estates-General of 1789
and was one of the 47 who joined the Estates of the Realm
that year. Dionis du Séjour died in Vernou-la-Celle-sur-Seine
.
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
astronomer
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
and mathematician
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
.
Dionis du Séjour was born in Paris
Paris
Paris is the capital and largest city in France, situated on the river Seine, in northern France, at the heart of the Île-de-France region...
and was a distant relative of surgeon and anatomist Pierre Dionis. He served as an advisor to parliament before he was appointed to the French Academy of Sciences
French Academy of Sciences
The French Academy of Sciences is a learned society, founded in 1666 by Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French scientific research...
in 1765. He was appointed to the Paris group for the Estates-General of 1789
Estates-General of 1789
The Estates-General of 1789 was the first meeting since 1614 of the French Estates-General, a general assembly representing the French estates of the realm: the nobility, the Church, and the common people...
and was one of the 47 who joined the Estates of the Realm
Estates of the realm
The Estates of the realm were the broad social orders of the hierarchically conceived society, recognized in the Middle Ages and Early Modern period in Christian Europe; they are sometimes distinguished as the three estates: the clergy, the nobility, and commoners, and are often referred to by...
that year. Dionis du Séjour died in Vernou-la-Celle-sur-Seine
Vernou-la-Celle-sur-Seine
Vernou-la-Celle-sur-Seine is a commune in the Seine-et-Marne department in the Île-de-France region in north-central France.-External links:* * * *...
.
Publications
- Traité des courbes algébriques (Treatise on Algebraic Curves), with Mathieu-Bernard Goudin (1756)
- Recherches sur le gnomonique et les rétrogradations des planètes (Research on sundials and retrograde motionRetrograde motionRetrograde motion is motion in the direction opposite to the movement of something else, and is the contrary of direct or prograde motion. This motion can be the orbit of one body about another body or about some other point, or the rotation of a single body about its axis, or other phenomena such...
s of Planets), (1761) - Traité des mouvements apparents des corps célestes (Treatise on apparent retrograde motion of celestial bodies), (1774)
- Essai sur les comètes (Essay on cometCometA comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s) (1775) - Essai sur les disparitions périodiques de l'anneau de Saturne (Essay on the periodic disappearance of the ring of Saturn), (1776)
External links
- Achille Pierre Dionis du Séjour biography via University of St. Andrews