Friedrich Tietjen (born October 15, 1832 in Garnholt , † June 21, 1895 in Berlin ) was a German astronomer . He worked continuously at the Berlin observatory from 1861 and discovered the asteroid (86) Semele in 1865 . From 1874 until his death he was the first director of the Astronomical Computing Institute founded at the observatory .
Youth and education
Tietjen came from a rural background and, according to his parents' wishes, was to take over his father's housekeeping job in Garnholt. He attended elementary school in Hüllstede from 1839 to 1847 and then worked on his parents' farm for some time. Even then, he showed mathematical talent and a great interest in observing the starry sky and, at the age of 20, received his father's approval to attend a school in Oldenburg and obtain his university entrance qualification. In 1853 Tietjen went to the Collegium Carolineum in Braunschweig to prepare for his studies of mathematics, physics and astronomy in Göttingen .
After completing his studies, Friedrich Tietjen moved to Berlin. There he observed planets and comets for a long time , being discovered as a young talent in 1859. In 1863 he received his doctorate on the methods of determining the orbits of planets and thus became a professor and doctor of astronomy. With this award he was appointed 1st assistant to the royal observatory.
In 1866 he received his first major commission from the Prussian king: together with the director of the observatory, he was supposed to look for a suitable point on the southern Jade Bay to survey northern Germany. He set the astronomical pillar of Dangast , which is used to define the Central European graticule according to an international agreement, and began surveying there on April 25, 1866. Through the measurements he and other researchers found out that the earth is not a sphere, but a so-called ellipsoid of revolution.
In 1868 Friedrich Tietjen became director of the Berlin observatory and was thus also the editor of the “Astronomical Yearbook”. In the same year he was assigned an expedition to India, during which he was supposed to observe a solar eclipse. He went on a week-long sea voyage, experienced the pulsating life in the oriental port cities while passing through and was personally welcomed in Bombay by the English governor. In his letters, which are still in the family's possession today, he described his long and exciting journey to India.
In the last phase of his life, Friedrich Tietjen worked again in Oldenburg, but still on behalf of the royal observatory in Berlin. He suffered from heart affections, asthma and as a result from severe shortness of breath, so his health caused him more and more difficulties. Tietjen traveled to the Mediterranean to relax and regularly wrote letters home. The hoped-for recovery did not materialize, however, on June 21, 1895 Friedrich Tietjen died as a result of his illness. Because of his attachment to his homeland and his family, he was buried in "homeland" in Westerstede . He did not leave any direct descendants as he had devoted all of his life and time to science instead of starting a family of his own.
Friedrich Tietjen became known far beyond the borders of Germany and was also highly valued abroad. His observations and scientific research were an important step in determining the astronomical distances and the movement of celestial bodies in space. But especially in his homeland, people were proud of the "Sterngucker" from Groß-Garnholt and the "Sternkieker Tietjen" was also popular in Berlin . Thanks to Tietjen, the Westersteders and Jeverans even knew about Otto von Bismarck's preferences and sent the Chancellor ham and lapwing eggs . Tietjen was very popular at court and was even invited to festivities, as one invitation attests.
The descendants of the Tietjen family today guard the last remaining pieces from the astronomer's life, including many private objects, documents and a large painting.
- In 1883 he became a member of the German Academy of Sciences Leopoldina .
- The asteroid (2158) Tietjen was named after him.
- Hermann Ries: The astronomer Friedrich Tietjen . In: Chronicle of the community Westerstede . Plois Verlag, Westerstede 1973, p. 258 f .
- Literature by and about Friedrich Tietjen in the catalog of the German National Library
- F. Tietjen's publications in the Astrophysics Data System
- Obituaries for F. Tietjen in the Astrophysics Data System
- Obituary in the Astronomical News bibcode : 1895AN .... 138..215F
|BRIEF DESCRIPTION||German astronomer|
|DATE OF BIRTH||October 15, 1832|
|PLACE OF BIRTH||Garnholt (now part of Westerstede )|
|DATE OF DEATH||June 21, 1895|
|Place of death||Berlin|