1784 – Born on the 22nd of July in Minden, Germany. German astronomer whose measurements of positions for about 50,000 stars allowed the first accurate determination of interstellar distances; he was the first to measure the distance of a star other than the Sun.
1799 – At the age of 14 he was apprenticed to the import-export concern Kulenkamp.
– He left school to become an apprentice to the commercial firm of Kulenkamp in Bremen.
1804 – Calculated the orbit of Halley’s comet from observations made by Thomas Harriot.
– Bessel wrote a paper on Halley’s comet, calculating the orbit using data from observations made by Harriot.
1805 – Became assistant in J. H. Schröters observatory at Lilienthal.
1806 – He accepted the post of assistant at the Lilienthal Observatory, a private observatory near Bremen.
1807 – He began to work on reducing James Bradley’s observations of the positions of 3222 stars made around at Greenwich.
1809-1810 – Bessel was appointed director of Frederick William III of Prussia’s new Königsberg Observatory and professor of astronomy.
1812 – He was elected to the Berlin Academy.
1813 – Acted as director in the observatory at Königsherg.
1821 – He observed all stars to the ninth magnitude in zones.
1824 – Developer and eponym of Bessel functions.
1825 – He was honored by election as a Fellow of the Royal Society.
1826 – Corrected the length of the seconds’ pendulum.
1829 – Awarded the Royal Astronomical Society Gold Medal with William Pearson and Heinrich Christian Schumacher.
1831-1832 – Measured an arc of the meridian in East Prussia.
1838 – His ascertainment of a parallax figure for the "Flying Star" 61 Cygni.
1841 – Received the Royal Astronomical Society Gold Medal.
1844 – Announced the binary character of Sirius and Procyon from their disturbed proper motions.
1846 – He died at Königsberg on the 17th of March in Königsberg, Prussia.