Friedrich Wilhelm August Argelander (22 March 1799 – 17 February 1875) was a German

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

. He is known for his determinations of stellar brightnesses, positions, and distances.

Life and work

Argelander was born in Memel in the

Kingdom of Prussia The Kingdom of Prussia (, ) was a German state that existed from 1701 to 1918.Marriott, J. A. R., and Charles Grant Robertson. ''The Evolution of Prussia, the Making of an Empire''. Rev. ed. Oxford: Clarendon Press, 1946. It played a signif ...

(now

Klaipėda Klaipėda ( ; ) is a city in Lithuania on the Baltic Sea coast. It is the List of cities in Lithuania, third-largest city in Lithuania, the List of cities in the Baltic states by population, fifth-largest city in the Baltic States, and the capi ...

Lithuania Lithuania, officially the Republic of Lithuania, is a country in the Baltic region of Europe. It is one of three Baltic states and lies on the eastern shore of the Baltic Sea, bordered by Latvia to the north, Belarus to the east and south, P ...

), the son of a father of Finnish descent, Johann Gottlieb Argelander, and

German German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

(

Prussia Prussia (; ; Old Prussian: ''Prūsija'') was a Germans, German state centred on the North European Plain that originated from the 1525 secularization of the Prussia (region), Prussian part of the State of the Teutonic Order. For centuries, ...

n) mother, Dorothea Wilhelmina Grünhagen. He studied with

Friedrich Bessel Friedrich Wilhelm Bessel (; 22 July 1784 – 17 March 1846) was a German astronomer, mathematician, physicist, and geodesy, geodesist. He was the first astronomer who determined reliable values for the distance from the Sun to another star by th ...

, whose assistant he became in 1820, and obtained his

Ph.D. A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of graduate study and original research. The name of the deg ...

in 1822 at

University of Königsberg The University of Königsberg () was the university of Königsberg in Duchy of Prussia, which was a fief of Poland. It was founded in 1544 as the world's second Protestant Reformation, Protestant academy (after the University of Marburg) by Duke A ...

. From 1823 until 1837, Argelander was the head of the Finnish

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysics, oceanography and volcanology are examples of disciplines for which observatories have been constructed. Th ...

, first in

Turku Turku ( ; ; , ) is a city in Finland and the regional capital of Southwest Finland. It is located on the southwestern coast of the country at the mouth of the Aura River (Finland), River Aura. The population of Turku is approximately , while t ...

and then in

Helsinki Helsinki () is the Capital city, capital and most populous List of cities and towns in Finland, city in Finland. It is on the shore of the Gulf of Finland and is the seat of southern Finland's Uusimaa region. About people live in the municipali ...

. He then moved to

Bonn Bonn () is a federal city in the German state of North Rhine-Westphalia, located on the banks of the Rhine. With a population exceeding 300,000, it lies about south-southeast of Cologne, in the southernmost part of the Rhine-Ruhr region. This ...

Germany Germany, officially the Federal Republic of Germany, is a country in Central Europe. It lies between the Baltic Sea and the North Sea to the north and the Alps to the south. Its sixteen States of Germany, constituent states have a total popu ...

. There he designed and built a new observatory at the

University of Bonn The University of Bonn, officially the Rhenish Friedrich Wilhelm University of Bonn (), is a public research university in Bonn, North Rhine-Westphalia, Germany. It was founded in its present form as the () on 18 October 1818 by Frederick Willi ...

with funding approved directly by King

Frederick William IV Frederick William IV (; 15 October 1795 – 2 January 1861), the eldest son and successor of Frederick William III of Prussia, was King of Prussia from 7 June 1840 until his death on 2 January 1861. Also referred to as the " romanticist on the t ...

whom Argelander had become friends with in his childhood. This lifelong friendship had started when the then crown prince temporarily lived in Argelander's parents house after the Prussian royal family fled to Memel after the

Battle of Jena–Auerstedt The twin battles of Jena and Auerstedt (; older spelling: ''Auerstädt'') were fought on 14 October 1806 on the plateau west of the river Saale in today's Germany, between the forces of Napoleon I of France and Frederick William III of Pruss ...

during the

Napoleonic Wars {{Infobox military conflict , conflict = Napoleonic Wars , partof = the French Revolutionary and Napoleonic Wars , image = Napoleonic Wars (revision).jpg , caption = Left to right, top to bottom:Battl ...

. Argelander excelled in developing effective, simple and fast methods for measuring star positions and magnitudes, thereby making a pioneering work for modern astronomy. He also measured star distances with

heliometer A heliometer (from Greek ἥλιος ''hḗlios'' "sun" and ''measure'') is an instrument originally designed for measuring the variation of the Sun's diameter at different seasons of the year, but applied now to the modern form of the instrumen ...

s. His, and his collaborators', great practical works of star cataloging and variable star research were made possible by the systematic usage of then newly developed techniques. Argelander was the first astronomer to begin a careful study of

variable star A variable star is a star whose brightness as seen from Earth (its apparent magnitude) changes systematically with time. This variation may be caused by a change in emitted light or by something partly blocking the light, so variable stars are ...

s. Only a handful were known when he began, and he was responsible for introducing the modern system of identifying them. He also made a rough determination of the direction in which the

Sun The Sun is the star at the centre of the Solar System. It is a massive, nearly perfect sphere of hot plasma, heated to incandescence by nuclear fusion reactions in its core, radiating the energy from its surface mainly as visible light a ...

was moving. In 1842, he discovered that

Groombridge 1830 Groombridge 1830 is a star 29.9 light-years away in the constellation Ursa Major. With an apparent magnitude of 6.4, it is near the limit of naked eye visibility under ideal conditions. It has a low metallicity and is thought to be a sup ...

had a very high

proper motion Proper motion is the astrometric measure of changes in the apparent places of stars or other celestial objects as they move relative to the center of mass of the Solar System. It is measured relative to the distant stars or a stable referenc ...

. For many decades its proper motion was the highest known; today it still occupies third place. For a time, it was known as ''Argelander's Star''. Together with

Adalbert Krüger Karl Nikolaus Adalbert Krueger (9 December 1832 – 21 April 1896) was a German astronomer. Born in Marienburg, Prussia (now Malbork, Poland), he was editor of '' Astronomische Nachrichten ''from 1881 until his death. Krueger died of a heart con ...

and

Eduard Schönfeld Eduard Schönfeld (22 December 18281 May 1891) was a German astronomer. Education Schönfeld was born at Hildburghausen, in the Duchy of Saxe-Meiningen, where he had a distinguished career at the gymnasium. On leaving the gymnasium, he desired t ...

, Argelander was responsible for the

star catalogue A star catalogue is an astronomical catalogue that lists stars. In astronomy, many stars are referred to simply by catalogue numbers. There are a great many different star catalogues which have been produced for different purposes over the year ...

known as the ''

Bonner Durchmusterung In astronomy, Durchmusterung or Bonner Durchmusterung (BD) is an astrometric star catalogue of the whole sky, published by the Bonn Observatory in Germany from 1859 to 1863, with an extension published in Bonn in 1886. The name comes from ('run-t ...

'', published between 1859 and 1862, which gave the positions and brightness of more than 324,000 stars, although it did not cover much of the southern half of the sky. This was the last star map to be published without the use of photography. In 1863, Argelander helped lead in the founding of an international organization of astronomers named the ''

Astronomische Gesellschaft __NOTOC__ The ''Astronomische Gesellschaft'' is an astronomical society established in 1863 in Heidelberg, the second oldest astronomical society after the Royal Astronomical Society. History In 1882, the ''Astronomische Gesellschaft'' founded t ...

''.

Honors and legacy

Friedrich Wilhelm August Argelander Carl Peter Mazer

* Elected a foreign member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences () is one of the Swedish Royal Academies, royal academies of Sweden. Founded on 2 June 1739, it is an independent, non-governmental scientific organization that takes special responsibility for promoting nat ...

in 1846. * Elected a Foreign Honorary Member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

in 1855. * Elected Member of the

Royal Academy of Science, Letters and Fine Arts of Belgium The Royal Academy of Science, Letters and Fine Arts of Belgium ( , sometimes referred to as ' ) is the independent learned society of science and arts of the French Community of Belgium. One of Belgium's numerous academies, it is the French-speak ...

. * Was awarded 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 1863. * Orden

Pour le Mérite The (; , ), also informally known as the ''Blue Max'' () after German WWI flying ace Max Immelmann, is an order of merit established in 1740 by King Frederick II of Prussia. Separated into two classes, each with their own designs, the was ...

für Wissenschaften und Künste (Order Pour le Mérite for Arts and Sciences - Civil class) in 1874. * The three astronomical institutes of the Bonn University were merged and renamed as the ''Argelander-Institut für Astronomie'' in 2006. * The crater Argelander on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

and the

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

1551 Argelander are named for him.

References and notes

;Citations

External links

* * *
''Neue Uranometrie'', 1843
- Full digital facsimile, Linda Hall Library.

{{DEFAULTSORT:Argelander, Friedrich Wilhelm 1799 births 1875 deaths People from Klaipėda Foreign members of the Royal Society Foreign associates of the National Academy of Sciences People from East Prussia 19th-century German astronomers Astronomers from the Kingdom of Prussia Recipients of the Gold Medal of the Royal Astronomical Society Academic staff of the University of Bonn University of Königsberg alumni Members of the Royal Academy of Belgium Members of the Royal Swedish Academy of Sciences Corresponding members of the Saint Petersburg Academy of Sciences Recipients of the Pour le Mérite (civil class) Demidov Prize laureates Fellows of the American Academy of Arts and Sciences German people of Finnish descent Members of the Göttingen Academy of Sciences and Humanities

Life and work

Honors and legacy

Further reading

See also

References and notes

External links