Julius August Koch

Julius August Koch (born June 15, 1752 in Osnabrück , † October 21, 1817 in Danzig ) was a German astronomer and doctor .

He majored in medicine in Göttingen and Strasbourg , and took mathematics and astronomy as minor subjects. After completing his doctorate, he settled in Osnabrück as a general practitioner.

In 1792, on the recommendation of his former teacher Lichtenberg , the Natural Research Society in Danzig appointed him to their observatory on Danzig's Bischofsberg, founded by Wolf in 1783, as an astronomer.

Due to the second siege of Danzig (1813, after 1807) that he experienced , his health suffered so much that he died three years after it ended.

Koch was one of the first astronomers to research the variability of fixed stars. In 1782 he discovered R Leonis , a variable star with a long period and large amplitude that was only temporarily visible to the naked eye. Other discoveries were variable stars in the constellations Hercules , Northern Crown and Shield . In Bode's yearbook for 1817 the "Table of all 1815 known variable stars whose light change periods have been determined" appeared. As an appendix to Bode 's tables, he had "Astronomical tables for determining the time from the same observed, although unknown altitude." Fixed stars ”(Berlin and Stralsund 1797) appear, which proved to be very useful for the seafarer. In Bode's yearbook for 1794 he discussed the question of whether comets could still be seen in their distance from the sun.

Individual evidence

1. ^ Siegmund Günther :  Koch, Julius August . In: Allgemeine Deutsche Biographie (ADB). Volume 16, Duncker & Humblot, Leipzig 1882, p. 393.