Camille Guillaume Bigourdan (; 6 April 1851 – 28 February 1932) was a French
astronomer
An astronomer is a scientist in the field of astronomy who focuses their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...
.
Personal life
Bigourdan was born at
Sistels,
Tarn-et-Garonne
Tarn-et-Garonne (; oc, Tarn e Garona ) is a department in the Occitania region in Southern France. It is traversed by the rivers Tarn and Garonne, from which it takes its name. The area was originally part of the former provinces of Quercy and ...
to Pierre Bigourdan and Jeanne Carrière. When his teachers and local curate recognised his intelligence, he was transferred to a local boarding school in Valence d’Agen, where he excelled. In 1870, he received his Baccalauréat with mention of “Assez Bien.”
He married Marie Mélanie Sophie Mouchez, the eldest daughter of Admiral
Amédée Mouchez
Ernest Amédée Barthélemy Mouchez (24 August 1821 – 29 June 1892) was a French naval officer who became director of the Paris Observatory and launched the ill-fated ''Carte du Ciel'' project in 1887.
Life
Born in Madrid, Spain, Mouchez emba ...
.
Together, the two had 9 children. The entire family, including the Mouchez cousins, would frequently vacation in Sistels until the outbreak of the First World War, after which Bigourdan would vacation alone. During these vacations, he would farm his land and visit former classmates.
He was fluent in Occitan, and spoke it when in Sistels.
Academic and Scientific Career
Bigourdan studied at the University of Toulouse from 1870, where he received a physics degree in 1874 and a mathematics degree in 1876. To finance these studies, he taught at a boarding school.
In 1877 he was appointed by
Félix Tisserand
François Félix Tisserand (13 January 1845 – 20 October 1896) was a French astronomer.
Life
Tisserand was born at Nuits-Saint-Georges, Côte-d'Or. In 1863 he entered the École Normale Supérieure, and on leaving he went for a month as profes ...
as assistant astronomer at the
Toulouse Observatory
The Toulouse Observatory (french: Observatoire de Toulouse) is located in Toulouse, France and was established in 1733.
It was founded by ''l'Académie des Sciences, Inscriptions et Belles-Lettres de Toulouse'' ("Academy of Science, Inscriptions ...
, and in 1879 followed Tisserand to the
Paris Observatory
The Paris Observatory (french: Observatoire de Paris ), a research institution of the Paris Sciences et Lettres University, is the foremost astronomical observatory of France, and one of the largest astronomical centers in the world. Its histor ...
when the latter became director there.
In 1886, he submitted his doctoral thesis ''Sur l"équation personnelle dans les mesures d"étoiles doubles'' (FR: On the personal equation in double star measurements) on the measurements of 2800 double stars.
He spent many years verifying the positions of 6380
nebula
A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming regio ...
e. He hoped to set a basis for future studies of the
proper motion
Proper motion is the astrometric measure of the observed changes in the apparent places of stars or other celestial objects in the sky, as seen from the center of mass of the Solar System, compared to the abstract background of the more dista ...
of nebulae; this turned out to be more or less in vain, since distant nebulae will not show any proper motion. However, he did discover approximately 500 new objects. These observations are published throughout 5 volumes of the ''Annales'' of the Paris observatory, over 3000 pages. Additionally, in 1894, Bigourdan discovered the asteroid 390 Ama.
Biogrourdan was an avid traveler for astrological events; he took part in the observation of the transit of venus in Martinique in June 1882. On the same trip, he visited St Petersburg, Kraków, Berlin and Vienna. In 1892, he visited Joal, Senegal, to observe the total eclipse of the sun on 16 April 1893.
In 1902 he participated in an effort to redetermine with greater precision the longitude difference between
London
London is the capital and largest city of England and the United Kingdom, with a population of just under 9 million. It stands on the River Thames in south-east England at the head of a estuary down to the North Sea, and has been a majo ...
and
Paris
Paris () is the capital and most populous city of France, with an estimated population of 2,165,423 residents in 2019 in an area of more than 105 km² (41 sq mi), making it the 30th most densely populated city in the world in 2020. S ...
. He became a member of the
Bureau des Longitudes in 1903, and a member of the
French Academy of Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...
in 1904.
Due to his interest in the transmission of time signals by wireless, he was instituted as the director of the newly founded International Time Service in 1913, which was in charge of maintaining the switch to the new Greenwich time.
He remained in this position until 1928.
He described a method for adjusting
equatorial mount
An equatorial mount is a mount for instruments that compensates for Earth's rotation by having one rotational axis, the polar axis, parallel to the Earth's axis of rotation. This type of mount is used for astronomical telescopes and cameras. The ...
telescopes, which was known as "
Bigourdan's method".
Bigourdan won the
Lalande Prize
The Lalande Prize (French: ''Prix Lalande'' also known as Lalande Medal) was an award for scientific advances in astronomy, given from 1802 until 1970 by the French Academy of Sciences.
The prize was endowed by astronomer Jérôme Lalande in 180 ...
of the
French Academy of Sciences
The French Academy of Sciences (French: ''Académie des sciences'') is a learned society, founded in 1666 by Louis XIV of France, Louis XIV at the suggestion of Jean-Baptiste Colbert, to encourage and protect the spirit of French Scientific me ...
in 1883 and in 1891, the
Valz Prize
The Valz Prize ''(Prix Valz)'' was awarded by the French Academy of Sciences, from 1877 through 1970, to honor advances in astronomy.
History
The Valz Prize was established in June 1874 when the widow of astronomer Benjamin Valz, Marie Madeleine J ...
of the same institution in 1886,
and the
Gold Medal of the Royal Astronomical Society
The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...
in 1919. He was director of the
Bureau International de l'Heure
The International Time Bureau (french: Bureau International de l'Heure, abbreviated BIH), seated at the Paris Observatory, was the international bureau responsible for combining different measurements of Universal Time.
The bureau also played an ...
from 1919 to 1928.
In 1919, he received the
Prix Jules Janssen, the highest award of the
Société astronomique de France, the French astronomical society. In 1924, he was made president of the Académie des Sciences and the Institute of France, after serving as its vice-president in 1923.
In addition, Gifourdan discovered various lost manuscripts, particularly those of J.A.G Pingré, and contributed to numerous historical studies.
He published ''Annales célestes'' ''du XVIIesiècle'' in 1901.
References
Further reading
*
External links
*
Awarding of RAS gold medalG. Bigourdan@
Astrophysics Data System
The SAO/NASA Astrophysics Data System (ADS) is an online database of over 16 million astronomy and physics papers from both peer reviewed and non-peer reviewed sources. Abstracts are available free online for almost all articles, and full scanned a ...
;Obituaries
JRASC 26 (1932) 276(one line)
{{DEFAULTSORT:Bigourdan, Guillaume
20th-century French astronomers
Discoverers of asteroids
1851 births
1932 deaths
Members of the French Academy of Sciences
Recipients of the Gold Medal of the Royal Astronomical Society
People from Tarn-et-Garonne
19th-century French astronomers
Recipients of the Lalande Prize