Johan Oskar Backlund (28 April 1846 – 29 August 1916) was a

Swedish Swedish or ' may refer to: Anything from or related to Sweden, a country in Northern Europe. Or, specifically: * Swedish language, a North Germanic language spoken primarily in Sweden and Finland ** Swedish alphabet, the official alphabet used by ...

Russia Russia (, , ), or the Russian Federation, is a List of transcontinental countries, transcontinental country spanning Eastern Europe and North Asia, Northern Asia. It is the List of countries and dependencies by area, largest country in the ...

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 ...

. His name is sometimes given as Jöns Oskar Backlund, however even contemporary Swedish sources give "Johan". In

, where he spent his entire career, he is known as Oskar Andreevich Baklund (Оскар Андреевич Баклунд). Russian sources sometimes give his dates of birth and death as 16 April 1846 and 16 August 1916, since Russia still used the

Julian calendar The Julian calendar, proposed by Roman consul Julius Caesar in 46 BC, was a reform of the Roman calendar. It took effect on , by edict. It was designed with the aid of Greek mathematicians and astronomers such as Sosigenes of Alexandr ...

at the time.

Life

He was born in Länghem, in

Västergötland Västergötland (), also known as West Gothland or the Latinized version Westrogothia in older literature, is one of the 25 traditional non-administrative provinces of Sweden (''landskap'' in Swedish), situated in the southwest of Sweden. Väs ...

Sweden Sweden, formally the Kingdom of Sweden,The United Nations Group of Experts on Geographical Names states that the country's formal name is the Kingdom of SwedenUNGEGN World Geographical Names, Sweden./ref> is a Nordic country located on ...

and graduated from

Uppsala University Uppsala University ( sv, Uppsala universitet) is a public university, public research university in Uppsala, Sweden. Founded in 1477, it is the List of universities in Sweden, oldest university in Sweden and the Nordic countries still in opera ...

in 1872. After getting his doctorate in 1875, he emigrated to Russia in 1876. He worked at Dorpat Observatory, in today's

Tartu Tartu is the second largest city in Estonia after the Northern European country's political and financial capital, Tallinn. Tartu has a population of 91,407 (as of 2021). It is southeast of Tallinn and 245 kilometres (152 miles) northeast of ...

Estonia Estonia, formally the Republic of Estonia, is a country by the Baltic Sea in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the sea across from Sweden, to the south by Latvia, a ...

, and then in 1879 worked at Pulkovo Observatory, becoming director of the observatory from 1895 until his death. He specialized in

celestial mechanics Celestial mechanics is the branch of astronomy that deals with the motions of objects in outer space. Historically, celestial mechanics applies principles of physics (classical mechanics) to astronomical objects, such as stars and planets, to ...

, and notably worked on calculating the orbit of Comet Encke, taking into account the perturbations of various planets. He used observations of Comet Encke to try estimate the mass of

Mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

. Russian sources sometimes referred to the comet as Comet Encke-Backlund. He also carried out

geodesic In geometry, a geodesic () is a curve representing in some sense the shortest path ( arc) between two points in a surface, or more generally in a Riemannian manifold. The term also has meaning in any differentiable manifold with a connection. ...

studies in

Spitzbergen Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...

from 1898 to 1900. He became a member of the

Saint Petersburg Saint Petersburg ( rus, links=no, Санкт-Петербург, a=Ru-Sankt Peterburg Leningrad Petrograd Piter.ogg, r=Sankt-Peterburg, p=ˈsankt pʲɪtʲɪrˈburk), formerly known as Petrograd (1914–1924) and later Leningrad (1924–1991), i ...

Academy of Sciences in 1883, member of the

Royal Swedish Academy of Sciences The Royal Swedish Academy of Sciences ( sv, Kungliga Vetenskapsakademien) 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 ...

in 1897 and

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the judges of the Royal Society of London to individuals who have made a "substantial contribution to the improvement of natural science, natural knowledge, incl ...

in 1911. He was elected a Foreign Honorary Member of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (abbreviation: AAA&S) 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 ...

in 1914.

Family

He was married to Ulrika Catharina Widebeck. Their daughter

Elsa Celsing Elsa Celsing (25 March 1880 – 19 April 1974), also known as Elsa Backlund-Celsing, was a Russian-Swedish artist known for her portraits, still lifes, and scenes of domestic life. Life Born Elsa Carolina Backlund, she was the daughter of Swedis ...

became a well-known artist, and their son

Helge Gotrik Backlund Helge or Helgi is a Scandinavian, German, and Dutch mostly male name. The name is derived from Proto-Norse ''Hailaga'' with its original meaning being ''dedicated to the gods''. For its Slavic version, see Oleg. Its feminine equivalent is Olga ...

(3 September 1878 – 1958) was a geologist and explorer.

Honors

Awards * Gold Medal of the Royal Astronomical Society (1909) * Bruce Medal (1914) Named after him *The crater

Backlund Backlund is a Swedish surname. Notable people with the surname include: * Albert Victor Bäcklund (1845-1922), mathematician * Bengt Backlund (1926–2006), Swedish flatwater canoer * Bob Backlund (born 1949), American professional wrestler * Fil ...

on the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

Asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...

856 Backlunda 856 Backlunda ( ''prov. designation'': ''or'' ) is a dark background asteroid from the inner region of the asteroid belt. It was discovered on 3 April 1916, by Russian astronomer Sergey Belyavsky at the Simeiz Observatory on the Crimean peninsul ...

Backlundtoppen Backlundtoppen is a mountain in Olav V Land at Spitsbergen, Svalbard. It has a height of 1,068 m.a.s.l. and is located east of Billefjorden and west of Akademikarbreen Akademikarbreen (until 1995 spelled Akademikerbreen) is a glacier in Ola ...

, a mountain in

Olav V Land Olav V Land is a peninsula in eastern Spitsbergen Island, Svalbard named after Olav V of Norway. It is covered by the Olav V Icefield, measuring about .''Glacier Atlas of Svalbard and Jan Mayen''. 1993. Oslo: Norsk polarinstitutt, p. 32. The o ...

Spitsbergen Spitsbergen (; formerly known as West Spitsbergen; Norwegian: ''Vest Spitsbergen'' or ''Vestspitsbergen'' , also sometimes spelled Spitzbergen) is the largest and the only permanently populated island of the Svalbard archipelago in northern Norw ...

Svalbard Svalbard ( , ), also known as Spitsbergen, or Spitzbergen, is a Norwegian archipelago in the Arctic Ocean. North of mainland Europe, it is about midway between the northern coast of Norway and the North Pole. The islands of the group range ...

References

External links

Bruce Medal page
in

Project Runeberg Project Runeberg ( sv, Projekt Runeberg) is a digital cultural archive initiative that publishes free electronic versions of books significant to the culture and history of the Nordic countries. Patterned after Project Gutenberg, it was founded ...

(in Swedish)
I:56 (Svenskt biografiskt handlexikon)
in Project Runeberg (in Swedish)

in Project Runeberg (in Swedish)

Obituaries

(in German)

{{DEFAULTSORT:Backlund, Oskar 1846 births 1916 deaths 19th-century Swedish astronomers Uppsala University alumni Members of the Royal Swedish Academy of Sciences Foreign Members of the Royal Society Foreign associates of the National Academy of Sciences Recipients of the Bruce Medal Recipients of the Gold Medal of the Royal Astronomical Society Fellows of the American Academy of Arts and Sciences Full members of the Saint Petersburg Academy of Sciences Academic staff of the University of Tartu Recipients of the Lalande Prize Privy Councillor (Russian Empire) 20th-century Swedish astronomers