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

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

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 ...

. 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 (

Russian Russian(s) may refer to: *Russians (), an ethnic group of the East Slavic peoples, primarily living in Russia and neighboring countries *A citizen of Russia *Russian language, the most widely spoken of the Slavic languages *''The Russians'', a b ...

: 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 is a solar calendar of 365 days in every year with an additional leap day every fourth year (without exception). The Julian calendar is still used as a religious calendar in parts of the Eastern Orthodox Church and in parts ...

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. Vä ...

Sweden Sweden, formally the Kingdom of Sweden, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. It borders Norway to the west and north, and Finland to the east. At , Sweden is the largest Nordic count ...

and graduated from

Uppsala University Uppsala University (UU) () 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 operation. Initially fou ...

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 Tallinn. Tartu has a population of 97,759 (as of 2024). It is southeast of Tallinn and 245 kilometres (152 miles) northeast of Riga, Latvia. Tartu lies on the Emajõgi river, which connects the ...

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

, and then in 1879 worked at

Pulkovo Observatory The Pulkovo Astronomical Observatory (), officially named the Central Astronomical Observatory of the Russian Academy of Sciences at Pulkovo, is the principal astronomical observatory of the Russian Academy of Sciences. It is located 19 km south ...

, 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 Comet Encke , or Encke's Comet (official designation: 2P/Encke), is a periodic comet that completes an orbit of the Sun once every 3.3 years. (This is the shortest period of a reasonably bright comet; the faint main-belt comet 311P/PanSTARRS has ...

, taking into account the perturbations of various planets. He used observations of Comet Encke to try estimate the mass of Mercury. 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 locally 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 conn ...

studies in

Spitzbergen Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of mainland Europe, it lies about midway between the northern coast o ...

from 1898 to 1900. He became a member of the

Saint Petersburg Saint Petersburg, formerly known as Petrograd and later Leningrad, is the List of cities and towns in Russia by population, second-largest city in Russia after Moscow. It is situated on the Neva, River Neva, at the head of the Gulf of Finland ...

Academy of Sciences in 1883, 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 1897 and

Fellow of the Royal Society Fellowship of the Royal Society (FRS, ForMemRS and HonFRS) is an award granted by the Fellows 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 (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 1914.

Family

He was married to Ulrika Catharina Widebeck. Their daughter Elsa Celsing became a well-known artist, and their son Helge Gotrik Backlund (3 September 1878–1958) was a geologist and explorer.

Honors

Awards *

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 ...

(1909) *

Bruce Medal The Catherine Wolfe Bruce Gold Medal is awarded every year by the Astronomical Society of the Pacific for outstanding lifetime contributions to astronomy. It is named after Catherine Wolfe Bruce, an American patroness of astronomy, and was ...

(1914) Named after him *The crater Backlund 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 ...

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 ...

856 Backlunda * Backlundtoppen, a mountain in

Olav V Land Olav V Land is a peninsula in eastern Spitsbergen Island, Svalbard Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. ...

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

Svalbard Svalbard ( , ), previously known as Spitsbergen or Spitzbergen, is a Norway, Norwegian archipelago that lies at the convergence of the Arctic Ocean with the Atlantic Ocean. North of continental Europe, mainland Europe, it lies about midway be ...

References

External links

Bruce Medal page
in

Project Runeberg Project 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 by Lars Aronsson and ...

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

in Project Runeberg (in Swedish) *https://www.genealogy.math.ndsu.nodak.edu/id.php?id=234324

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 Swedish emigrants Immigrants to the Russian Empire 19th-century astronomers from the Russian Empire