Viktor Knorre was born on 4th October 1840 in Nikolayew, southern Russia, as the fifth of 15 children. His father, Karl Friedrich Knorre (see below), was Director of the astronomical Observatory there until 1871. Viktor's father sent him to school in Fellin, Estonia. This was necessary since the educational situation was difficult in Russia then. Viktor returned home after he finished school andhelped his father at the Observatory for two years. In 1862 he left for Berlin, Germany, to study Astronomy with W. Foerster. After his doctoral thesis he went to Pulkowa in 1867 as an astronomical calculator. During his time there he travelled with a Mr. Wild to inspect some meteorological stations and made observations to get the exact location of these stations. He also made magnetic observations.
In 1869 Viktor returned to Nikolayew where he first taught his younger brothers and sisters and then got a post as teacher at the local school. It seems that he earned a lot of praise but got no money for his work; he left for Berlin again to meet his father who went there after retiring from his post in Nikolayew. Viktor soon joined the Berlin Observatory as an Observer where he used the Refractor made by Fraunhofer. His main work involved minor planets, comets and binary stars. On the 4th of January 1876 he discovered minor planet  Koronis, in later years followed by  Oenone,  Hypatia and  Penthesilea. For the observations of minor planets he constructed a micrometer which he described in its various stages of development in the 'Astronomische Nachrichten'.
Viktor Knorre also worked on the improvement of other instruments and equatorial telescope mountings. He did not take a post in teaching students at the University in Berlin but was always helpful in introducing new users to the telescopes.
In 1892 he was appointed Professor. In 1906 he retired and moved to Lichterfelde, close to Berlin, where he owned a house. He found recreation from his ongoing scientific work while working in the garden or playing Chess. In 1909 and 1911 he published works on a new equatorial telescope mounting type 'Knorre & Heele'. A prototype was made by Heele at Knorre's expenses.
Viktor Knorre died on the 25th August 1919 in Lichterfelde after a short illness.
References: 1. Poggendorff, Vol. 3 (1898), p. 731 2. Poggendorff, Vol. 5 (1925), p. 646 3. Astronomische Nachrichten, Vol. 209 (1919), p. 367
Karl Friedrich Knorre was born 28th March 1801, died 10th September 1883 in Berlin. His father was Ernst Christoph Friedrich Knorre, see below for details. During a trip in 1825 he visited J.F. Encke at the Seeberg Observatory near Gotha and joined him in observations of a comet. Encke referres to him as 'Professor Knorre', so he seems to have been a well respected person at the age of 24. The comet observed was 'Comet Encke', but he (Encke) always referred to it as 'Comet Pons'.
K.F. Knorre retired 1871 from the Directorship of the Observatory in Nikolajew and moved to Berlin. One of his 15 children (Victor, see above) followed his interest in Astronomy.
Reference: 1. Poggendorff, Vol. 3 (1898), p. 730-731 2. ENCKE, J.F., in: Astronomische Nachrichten, Vol. 4, (1826), p. 227
Ernst Christoph Friedrich Knorre was born 1759 in Neuhaldensleben near Magdeburg (Germany), died in Dorpat 1st December 1810.E.C.F. Knorre studied Theology in Halle and worked as a private teacher in the house of the bookseller Gebauer. 1789 he went to Dorpat as the Director of a girls' school. After the founding of a University in Dorpat he was Professor for Mathematics there and Observer at the new Observatory. He kept this dual function until his death in 1810. His astronomical observations were limited since the Observatory was not completed when he died. Some of his observations have been published by Bode. Other publications by Knorre included "Leitfaden bey meinen mathematischen Vorlesungen" (Dorpat 1803) and "Leitfaden fuer den Religionsunterricht in der Toechterschule zu Dorpat".
Reference: 1. Allg. Deutsche Biographie, Vol. 16, p. 328