Camille Guillaume Bigourdan
April 6, 1851 – February 28, 1932
Guillaume Bigourdan was a French astronomer. In 1877 he was appointed by Félix Tisserand as assistant astronomer at the Toulouse Observatory, and in 1879 followed Tisserand to the Paris Observatory when the latter became director there.
He spent many years verifying the positions of 6,380 nebulas. He hoped to set a basis for future studies of the proper motion of nebulas; this turned out to be more or less in vain, since distant nebulas will not show any proper motion. However, he did discover approximately 500 new objects, including asteroid 390 Alma (on March 24, 1894).
In 1902 he participated in an effort to redetermine with greater precision the longitude difference between London and Paris. He became a member of the Bureau des Longitudes in 1903, and a member of the French Academy of Sciences in 1904.
He described a method for adjusting equatorial mount telescopes, which was known as "Bigourdan's method".
Bigourdan won the Gold Medal of the Royal Astronomical Society in 1919 for his observations of nebulae for over 25 years. He was director of the Bureau International de l'Heure from 1919 to 1928.