Nicolas-Louis de Lacaille

from Wikipedia, the free encyclopedia
Nicolas Louis de Lacaille (1713–1762)

Nicolas-Louis de Lacaille (March 15, 1713 in Rumigny , Ardennes Department , † March 21, 1762 in Paris ), also known as the Abbé de La Caille , was a French astronomer who named 14 of the 88 modern constellations .

Live and act

Lacaille studied theology , but then devoted himself more to mathematics and astronomy and gave up the theological career entirely. In 1739/1740 he and César François Cassini de Thury carried out a meridian survey near Paris to determine the circumference of the earth. In 1741 he became a member of the Paris Academy .

In 1746 he was given the chair of mathematics at the Collège Mazarin and in this position made great contributions to the correction of the star catalogs and the astronomical tables.

In 1750 he traveled to the Cape of Good Hope for four years to calculate the parallaxes of the moon , Venus and Mars more precisely. His position determinations contributed to determining the distances of these celestial bodies more precisely than possible up to then. He also observed the constellations of the southern sky and cataloged almost 10,000 stars. He also discovered several foggy objects such as the Messier 83 galaxy , which were later included in the Messier catalog of the astronomer Charles Messier . His Coelum Australe Stelliferum was published posthumously in 1763. He also measured a degree of latitude in the southern hemisphere and provided a map of the islands of Mauritius (then Île de France ) and Réunion (then Île de Bourbon ).

In 1754 he returned to Paris and made astronomical observations and calculations with tireless zeal until his death. From 1741 he belonged to the Académie des Sciences . In December 1755 he became an honorary member of the Russian Academy of Sciences in St. Petersburg . In 1758 he was elected a foreign member of the Göttingen Academy of Sciences .

The position measurements he carried out on fixed stars in South Africa also confirmed the correctness of Isaac Newton's assumption that the earth is not a sphere, but rather - due to centrifugal force - must have a larger diameter at the equator than from pole to pole. Lacaille came to the conclusion, however, that the curvature is less (flatter) in the southern hemisphere than in the northern hemisphere. This is known as the meridian problem .

The lunar crater La Caille and the asteroid (9135) Lacaille were named after him.

Constellations according to Lacaille

The constellations named by Lacaille are (with today's names): Antlia , Caelum , Circinus , Fornax , Horologium , Mensa , Microscopium , Norma , Octans , Pictor , Pyxis , Reticulum , Sculptor and Telescopium .

Works

Leçons elementaires d'astronomie, géométrique et physique , 1755

Important publications by Lacaille are:

  • Leçons d'astronomie (Paris 1746; reissued by Jérôme Lalande , Paris 1780)
  • Éphémérides des mouvements célestes depuis 1745–75 (Paris 1745–63, continued by Lalande)
  • Planisphère des Étoiles Australes , dated 1752, published 1756 - this is where his newly introduced constellations appear for the first time
  • Astronomiae fundamenta (Paris 1757)
  • Leçons élémentaires de mécanique (Paris 1757; Latin edition Vienna 1759: digitized version )
  • Observations faites au cap de Bonne-Espérance (Paris 1763)
  • Coelum australe stelliferum (published by Jean-Dominique Maraldi , Paris 1763)
  • Observations sur 515 étoiles du zodiaque (published by Jean Sylvain Bailly , Paris 1763)
  • Tables solaires (Paris 1758)
  • Tables de logarithmes (Paris 1760)

Web links

Commons : Nicolas Louis de Lacaille  - Collection of images, videos and audio files

Individual evidence

  1. ^ List of members since 1666: Letter L. Académie des sciences, accessed on January 7, 2020 (French).
  2. ^ Foreign members of the Russian Academy of Sciences since 1724: Lacaille, Nicolas-Louis de. Russian Academy of Sciences, accessed January 7, 2020 (Russian).
  3. ↑ Holger Krahnke: The members of the Academy of Sciences in Göttingen 1751-2001 (= Treatises of the Academy of Sciences in Göttingen, Philological-Historical Class. Volume 3, Vol. 246 = Treatises of the Academy of Sciences in Göttingen, Mathematical-Physical Class. Episode 3, vol. 50). Vandenhoeck & Ruprecht, Göttingen 2001, ISBN 3-525-82516-1 , p. 143.
personal data
SURNAME Lacaille, Nicolas-Louis de
ALTERNATIVE NAMES Lacaille, Nicolas Louis de
BRIEF DESCRIPTION French astronomer, namesake of constellations
DATE OF BIRTH March 15, 1713
PLACE OF BIRTH Rumigny (Ardennes)
DATE OF DEATH March 21, 1762
Place of death Paris