Friedrich Wilhelm Bessel
The son of a poor government employee Friedrich Wilhelm Bessel was born on July 22nd 1784.
The German astronomer was born in Konigsberg, Prussia. With little formal education he went on to study astronomy and mathematics and in 1810 was appointed professor of astronomy at the University of Konigsberg.
Bessel measured the positions of about 50,000 stars. In 1838 he became the first person by using the parallax method to work the distance to a star other than the Sun. The star was 61 Cygni and was 10.3 light years away.