Fritz Cohn

Fritz Cohn was born on 12 May 1866 in Königsberg, Prussia, the second of three sons to the merchant Callman Cohn and his wife Henriette Rosenberg. When he was 11 his father died, after which his family experienced serious financial troubles. From 1872 he attended the Altstadt Gymnasium in his hometown, passing his matriculation exam in Easter 1883, at the age of 17. The following years were devoted to the study of mathematics, physics, and astronomy, as well as geography and history, at the University of Königsberg and the University of Berlin. In 1888 he passed Königsberg's state examinations and later in the same year attained a PhD with a thesis titled "Über Lamésche Funktionen mit komplexen Parametern" ("About Lamé functions with complex parameters"). == Career and later life ==

On 1 July 1891 he began working as a "computer" at the Königsberg Observatory. Save for a year's leave to further his studies in Leipzig, Cohn remained at the observatory until 1 October 1909, being promoted to an assistantship in 1898 and becoming a full-time observer in 1900. During this time he published numerous academic papers, among the major works being a discussion of the meteorological records of Königsberg for 45 years, a new reduction of observations made by Friedrich Bessel between 1813 and 1819, and a study of the declinations and proper motions of the stars selected for observation by the International Latitude Service. In 1893 he also attained the habilitation with a thesis titled "Über die in rekurrierender Weise gebildeten Größen und ihren Zusammenhang mit den algebraischen Gleichungen" ("On Recurring Values and Their Connection with Algebraic Equations"), allowing him to teach astronomy and mathematics at the University of Königsberg, leading to Cohn becoming an associate professor in 1985. His right ascension computations were considered "among the best of their kind." The resolutions decided at the conference reduced the workload of the institute and allowed Cohn to focus his resources towards studying the minor planets, which the institute was best known for. With the number of minor planets rapidly increasing, and the inaccuracies of past observations leading to them being frequently lost, Cohn created a principle under which, with the exception of preliminary computations, all orbits were to have an accuracy of ±15° in longitude. He personally oversaw the implementation of this principle and found success, reclaiming many objects believed to be lost. Even in the final year of his life he repeatedly affirmed that he planned to reclaim most lost minor planets within a few years. Upon his return home from a lecture given on 11 December 1922, Cohn suddenly encountered serious stomach pain and underwent surgery the following morning. He died in the aftermath of the operation attempt, on 14 December. It is likely that the illness was unnoticed stomach cancer. == Personal life ==

Outside of his work as an astronomer, Cohn was known as an avid gardener, often spending hours tending his plants. Personality Those who came in contact with Cohn often found him to be an agreeable, sociable, and intellectually stimulating person. J. Peters, a colleague and friend who wrote Cohn's most comprehensive obituary, said the following of him:Paul Viktor Neugebauer, who also described Cohn as "socially inclined" and "a most agreeable companion," said the following: == Honours ==

Namesakes • 972 Cohnia, named by Max Wolf and Gustav Stracke; == Memorials ==

Obituaries • • • • Other biographies • == Publications ==

An extensive list of Cohn's publications can be found on the Astrophysics Data System. == See also ==