Louis Thollon (2 May 1829 – 8 April 1887) was a French astronomer.
He was born in
Ambronay
Ambronay () is a commune in the Ain department in the Auvergne-Rhône-Alpes region of eastern France.
Geography
The commune of Ambronay is at the centre of a semicircle of mountains at the foot of the westernmost foothills of the Jura Mountain ...
,
France
France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of overseas regions and territories in the Americas and the Atlantic, Pacific and Indian Oceans. Its metropolitan area ...
.
[ Beginning in 1881, Thollon joined the staff of the new ]Nice Observatory
The Nice Observatory (french: Observatoire de Nice) is an astronomical observatory located in Nice, France on the summit of Mount Gros. The observatory was founded in 1879, by the banker Raphaël Bischoffsheim. The architect was Charles Garni ...
where he undertook a long-term observation program of the Sun using a spectroscope
An optical spectrometer (spectrophotometer, spectrograph or spectroscope) is an instrument used to measure properties of light over a specific portion of the electromagnetic spectrum, typically used in spectroscopic analysis to identify mate ...
of his own design.[ In the process, he recorded a solar ]spectrum
A spectrum (plural ''spectra'' or ''spectrums'') is a condition that is not limited to a specific set of values but can vary, without gaps, across a continuum. The word was first used scientifically in optics to describe the rainbow of colors ...
consisting of 3,000 absorption lines in the optical band.[
In 1882, he joined André Puiseux on an expedition to ]Egypt
Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a transcontinental country spanning the northeast corner of Africa and southwest corner of Asia via a land bridge formed by the Sinai Peninsula. It is bordered by the Medit ...
to observe the solar eclipse on 17 May.[ The same year he traveled to ]Portugal
Portugal, officially the Portuguese Republic ( pt, República Portuguesa, links=yes ), is a country whose mainland is located on the Iberian Peninsula of Southwestern Europe, and whose territory also includes the Atlantic archipelagos of ...
to watch the Venus transit
frameless, upright=0.5
A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and a superior planet, becoming visible against (and hence obscuring a small portion of) the solar disk. During a trans ...
, but was met with disappointment due to poor weather.[ He was awarded the Prix Lalande in 1885 for his large map of the solar system, which was not published until after his death in 1890.][Hentschel K. (2007) Thollon, Louis. In: Hockey T. et al. (eds) The Biographical Encyclopedia of Astronomers. Springer, New York, NY] During the 1886 Mars opposition
Opposition may refer to:
Arts and media
* ''Opposition'' (Altars EP), 2011 EP by Christian metalcore band Altars
* The Opposition (band), a London post-punk band
* '' The Opposition with Jordan Klepper'', a late-night television series on Com ...
, he assisted the observatory director, Henri Perrotin, in observing the planet with a reflecting telescope. Both men reported that they spotted '' canali'' on the surface of the planet, apparently confirming the 1877 discovery of these features by Italian astronomer Giovanni Schiaparelli
Giovanni Virginio Schiaparelli ( , also , ; 14 March 1835 – 4 July 1910) was an Italian astronomer and science historian.
Biography
He studied at the University of Turin, graduating in 1854, and later did research at Berlin Observatory, ...
.[ Thollon died at age 57 in ]Lyon
Lyon,, ; Occitan language, Occitan: ''Lion'', hist. ''Lionés'' also spelled in English as Lyons, is the List of communes in France with over 20,000 inhabitants, third-largest city and Urban area (France), second-largest metropolitan area of F ...
, France.[
]
References
{{DEFAULTSORT:Thollon, Louis
1829 births
1887 deaths
19th-century French astronomers
Recipients of the Lalande Prize