View source for Philippe Gustave le Doulcet, Comte de Pontécoulant

{{Short description|French astronomer}}
{{Infobox person
| name       = Philippe Gustave le Doulcet de Pontécoulant
| image      = Père-Lachaise - Division 60 - Le Doulcet de Pontécoulant 01.jpg
| image_size =
| caption    = Grave of Philippe Gustave le Doulcet de Pontécoulant
| birth_name =
| birth_date = 21 June 1795
| birth_place=
| death_date = {{death-date and age|21 July 1874|21 June 1795}}
| death_place = [[Pontécoulant]]
| death_cause=
| resting_place = [[Père Lachaise Cemetery]]
| known_for  = [[Astronomy]]
| parents    = [[Louis Gustave le Doulcet, comte de Pontécoulant]]
}}
'''Philippe Gustave Doulcet''', [[Count|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.<ref>George Forbes, "History of Astronomy".</ref>
He was a member of the [[French Academy of Sciences]]. The crater [[Pontécoulant (crater)|Pontécoulant]] on the [[Moon]] is named after him.<gallery>
File:Pontécoulant-1.jpg|Volumes I-III of ''Theorie analytique du systeme du monde'' (1829-1834)
File:Pontécoulant-2.jpg|Title page to volume I of ''Theorie analytique du systeme du monde'' (1829)
File:Pontécoulant-4.jpg|Table of contents to volume I of ''Theorie analytique du systeme du monde'' (1829)
File:Pontécoulant-7.jpg|First page to volume I of ''Theorie analytique du systeme du monde'' (1829)
</gallery>
==Bibliography==
* [https://libserv.aip.org/ipac20/ipac.jsp?session=167087C4B97V1.826507&profile=rev-all&source=~!horizon&view=subscriptionsummary&uri=full=3100006~!44280~!1&ri=2&aspect=power&menu=search&ipp=20&spp=20&staffonly=&term=Theorie+analytique+du+systeme+du+monde&index=.GW&uindex=&aspect=power&menu=search&ri=2 1829-1846, "Théorie Analytique du Système du Monde", Paris.]
* 1840, "Traité élémentaire de Physique Céleste", Paris, 2 volumes.
* 1864, "Notice sur la comète de Halley et ses apparitions successives de 1531 à 1910", ''Comptes rendus hebdomadaires des séances de l’Académie des sciences'', 58, 706-709
==References==
{{Reflist}}
==External links==
* [http://digitalcollections.ucsc.edu/cdm/compoundobject/collection/p265101coll10/id/1478/rec/1 Portrait of Gustave Pontecoulant from the Lick Observatory Records Digital Archive, UC Santa Cruz Library's Digital Collections]
{{Authority control}}
{{DEFAULTSORT:Pontecoulant, Philippe Gustave Doulcet, Compte de}}
[[Category:1795 births]]
[[Category:1874 deaths]]
[[Category:19th-century French astronomers]]
[[Category:Members of the French Academy of Sciences]]
[[Category:Counts of Pontécoulant]]
[[Category:19th-century French mathematicians]]
[[Category:French military personnel of the Napoleonic Wars]]
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