Karl Friedrich Knorre

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Karl Friedrich Knorre

Karl Friedrich Knorre (born March 28, 1801 in Dorpat , † August 29, 1883 in Berlin ) was a Russian astronomer of German descent.

Life path

Karl Friedrich Knorre belonged to a family of astronomers. Even his father, Ernst Christoph Friedrich Knorre , who came from Neuhaldensleben near Magdeburg , was between 1803 and 1810 in Dorpat (today: Tartu ) the observatory of the local observatory and professor of mathematics at the Imperial University .

Since the father died when Karl Friedrich was only nine years old, he grew up with his uncle Karl Senff . He was a hardworking student and finished school very early. At the age of 15 he studied at Dorpat University. Like his father, he had a penchant for mathematics and astronomy. However, at the request of his uncle and guardian, Karl Knorre began studying theology. At the same time, however, he also started studying mathematics. The astronomer Friedrich Georg Wilhelm Struve , who later became director of the Dorpat observatory, became aware of him. He supported Karl Knorre's self-study and instructed him in the practice of astronomy.

At that time, Struve was conducting an extensive land survey of Livonia . He took Karl Knorre with him as one of his assistants. When a request came from Admiral Alexey Greigh (Alexei Samuilowitsch Greig, 1775-1845), Russian admiral and from 1816 to 1833 commander of the Black Sea Fleet, for an astronomer for the construction of the observatory in Nikolayev (today: Mykolaiv ) on the Black Sea , suggested Struve Karl Knorre. On July 7, 1820, the Minister of the Russian Navy Jean-Baptiste Prevost de Sansac de Traversay (1754-1831) sent the certificate of appointment as a naval astronomer for the Black Sea Fleet.

At his own request, Karl Knorre was allowed to continue studying in Dorpat for half a year. He arrived in Nikolaev a month before his twentieth birthday. The construction of the observatory was under the direction of Admiral Greig,

Knorre family coat of arms

Karl Knorre took care of the astronomical instruments. To get an overview, he traveled across Europe for two years and visited the leading observatories and manufacturers of optical instruments and precise chronographs . Among other things, he met astronomers such as Friedrich Wilhelm Bessel , Johann Franz Encke , Heinrich Christian Schumacher in Altona and François Arago in Paris, with whom he later maintained correspondence. During and after his trip he ordered the instruments for the observatory, which were among the best in the world at the time, such as a three-foot meridian circle from Ertel, a five-foot refractor with a four-inch lens from Utzschneider and Fraunhofer. One of the special features was an artificial horizon that consisted of a sliding basin filled with mercury. The observations could be made both directly and indirectly via the artificial horizon in order to reduce observation errors. During his time as director of the observatory, he also taught nautical science in the naval school. In the course of his years of service he reached the rank of Privy Council . On October 24, 1871, shortly before retirement, he was finally entered in the register of the hereditary nobility of the Nobility Assembly of the Kherson Province .

After handing over the observatory to his successor, he moved to Berlin, where he was followed by his son Viktor Knorre , who from 1873 worked as an observator at the Berlin observatory. Due to the ennoblement that took place in Russia, since moving to Berlin he had the suffix "von", which was continued by the families of his children. As a result of the merits of their father Ernst Christoph Friedrich Knorre, his brother Carl Theodor Adolph Knorre was awarded a hereditary coat of arms, which the Karl Friedrich Knorre family has since led in a slightly modified form (without a monkshood branch and with a different arrangement of the stars in the coat of arms) .

Karl Knorre was married three times, to Elisabeth von Dieterichs, Dorothea von Dieterichs and Emilie von Gavel. He was the father of 18 children.

Achievements as an astronomer

One of his most important achievements was the production of the sheet Hora IV of the Berlin Academic Star Maps . Thanks to the very precise observations that Karl Knorre recorded on this map, small planets such as Astraea could be discovered . However, he had to give up processing another sheet that he had started due to other burdens. Another achievement of Knorre was an optimization of the sextant.

In 2010 the asteroid (14339) Knorre was named after him, his father and his son Viktor.

literature

Web links

Individual evidence

  1. ↑ GM Petrov, GI Pinigin: Karl Knorre, first astronomer of the Black Sea Fleet. , Nikolajew, 2007, translated by Suzanne Héral and Friedgard von Knorre, 2010.
  2. ↑ Award of the hereditary coat of arms of the Knorre family , April 24, 1870.
  3. ↑ Georg von Knorre: Von Knorre and Knorre Neuhaldensleben (including family tree). Typescript, Oschersleben, October 1972, p. 2.
  4. ↑ This is documented in the records of the Royal Astronomical Society, bibcode : 1889MNRAS..49S.169.
  5. ^ Jürgen Hamel : Bessel's project of the Berlin academic star maps. In: The Stars. Vol. 65 (1989), pp. 11-19.
  6. ↑ Astronomische Nachrichten No. 158, 1829, p. 262, doi : 10.1002 / asna.18290071704 .
  7. ↑ Minor Planet Circ. 69493
personal data
SURNAME Knorre, Karl Friedrich
ALTERNATIVE NAMES Knorre, Karl
BRIEF DESCRIPTION Russian astronomer
DATE OF BIRTH March 28, 1801
PLACE OF BIRTH Dorpat
DATE OF DEATH August 29, 1883
Place of death Berlin