Friedrich Wilhelm Bessel

German astronomer and mathematician Friedrich Wilhelm Bessel (Friedrich Wilhelm Bessel) (1784-1846) was born in the small town of Minden in north-west of Germany in the family a petty official. His life journey Bessel began salesclerk. Earnestly engaged in self-education, he quickly and successfully mastered the knowledge of mathematics and astronomy. For 20-year old boys Bessel independently calculated the orbit of Halley's Comet. Becoming an assistant to the astronomer and large. Schroeter, Bessel engaged in observations of stars. This work soon earned him the reputation of a prominent astronomer and calculator and mathematics.
In 1810, Mr.. Bessel was invited to Koenigsberg, where he became professor of astronomy at the University of KцІnigsberg. Here, under his leadership the observatory was built, the director where he remained until the end of his life.
Bessel - one of the founders of the astrometry. He has consistently implemented the idea of the need to make amendments to the results of observations, taking into account the influence of the most seemingly minor factors, which could decrease the accuracy of astrometric measurements. Bessel has developed a rigorous mathematical methods of correction results nablyudeniy.Pervoy Bessel great work in this direction was processing the results of observations of the stars in the catalog, compiled in 40-50-ies. 18 century British astronomer J. Bradleem. Later he led the Bessel observations of stars. He defined the position 75000 of thousands of stars and created extensive star catalogs, which became the basis of current knowledge about the starry sky.
Bessel was one of the first astronomers measure the parallax, and thus the distance to stars. After V.Ya. Struve, who in 1837. first determined the distance to the star Vega in the constellation Lyra, Bessel in 1838, Mr.. measured the distance to the star 61 Cygni. This star was one of the closest solar system.
Watching over the years, the bright stars Sirius and Procyon, Bessel found in their movement such features, which can be explained only by the fact that these stars have satellites. However, these satellites are so weak on the luminosity, that they can not be seen in telescopes. Assumption Bessel subsequently confirmed: in 1862. detected companion star Sirius, and in 1896. - Satellite Procyon.