Bessel, Friedrich Wilhelm

Friedrich Wilhelm Bessel, (born July 22, 1784, Minden, Brandenburg [now in Germany]—died March 17, 1846, Königsberg, Prussia [now Kaliningrad, Russia]), German astronomer whose measurements of positions for about 50,000 stars and rigorous methods of observation (and correction of observations) took astronomy to a new level of precision. He was the first to measure accurately the parallax, and hence the distance, of a star other than the Sun.