Date of Birth: 03/22/1799
Place of birth: Memel
German astronomer. Born March 22, 1799 in Memel (now Klaipeda). In 1822 he graduated from the University of Konigsberg. From 1820 he worked as an assistant in F.Besselya Koenigsberg observatory. In 1823 he moved to Finland. In 1823-1832 was the director of the observatory in Turku, then to 1836 - in Helsingfors. Since 1837 - a university professor and director of the observatory in Bonn.
Argelander engaged mainly positional astronomy and the study of the proper motions of stars. According to the materials of these observations was a catalog of 560 stars (1835). After analyzing the proper motions of 390 stars, I received confirmation of the solar system move in the direction of the constellation Hercules (this idea was first suggested V.Gershelem). In 1843 he published an atlas and catalog of all the stars visible to the naked eye. In 1838 Argelander started observations of variable stars and led these observations to 1870. He received more than 12,000 brightness estimates about 40 such stars, opened a large number of new, introduced their range. In 1852-1859 he led the creation of the Bonn Ferris (Bonner Durchmusterung) - fundamental catalog and atlas of all the stars of the sky in the Northern Hemisphere brighter 9th magnitude (more than 324 thousand stars.).
Died Argelander in Bonn February 17, 1875.