Oskar Backlund

Johan Oskar Backlund was a Swedish-Russian astronomer. His name is sometimes given as Jöns Oskar Backlund, however even contemporary Swedish sources give "Johan". In Russia, where he spent his entire career, he is known as Oskar Andreevich Baklund. 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 at the time.