Johan Oskar Backlund (28 April 1846 – 29 August 1916) was aSwedish-Russianastronomer. His name is sometimes given asJöns Oskar Backlund, however even contemporary Swedish sources give "Johan". InRussia, where he spent his entire career, he is known asOskar Andreevich Baklund (Russian: 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 theJulian calendar at the time.
He was born in Länghem, inVästergötland,Sweden and graduated fromUppsala University in 1872. After getting his doctorate in 1875,[1] he emigrated to Russia in 1876. He worked atDorpat Observatory, in today'sTartu,Estonia, and then in 1879 worked atPulkovo Observatory, becoming director of the observatory from 1895 until his death.
He specialized incelestial mechanics, and notably worked on calculating the orbit ofComet Encke, taking into account the perturbations of various planets. He used observations of Comet Encke to try estimate the mass ofMercury. Russian sources sometimes referred to the comet as Comet Encke-Backlund. He also carried outgeodesic studies inSpitzbergen from 1898 to 1900. He became a member of theSaint Petersburg Academy of Sciences in 1883, member of theRoyal Swedish Academy of Sciences in 1897 andFellow of the Royal Society in 1911. He was elected a Foreign Honorary Member of theAmerican Academy of Arts and Sciences in 1914.[2]
He was married to Ulrika Catharina Widebeck. Their daughterElsa Celsing became a well-known artist, and their sonHelge Gotrik Backlund (3 September 1878–1958) was a geologist and explorer.
Awards
Named after him
