Johann Tobias Bürg

Background

Johann Tobias Bürg was born on December 24, 1766, in Vienna, Austria.

Education

His parents were poor, and Bürg was destined to become a craftsman, until he received a fellowship from the Imperial Commission for Education. At the University of Vienna, he studied mathematics and astronomy under Triesnecker and Hell.

Career

Johann Bürg became a physics teacher at the lyceum of Klagenfurt, Carinthia, in 1791, and the following year he returned to Vienna as assistant at the university observatory. After 1802 Bürg travelled. For two years he was calculator at the observatory of Seebergen, near Gotha, under Zach. After his return to Vienna, he worked again at the university observatory and became professor of mathematics and astronomy at the university in 1806.

From 1808, Bürg suffered from progressive deafness. In 1813 he took a leave of absence from his teaching duties. In 1817 he succeeded as director at the Vienna Observatory after the death of Franz de Paula Triesnecker. Bürg retired in 1819. He lived in Vienna until 1825, when he moved to Wiesenau, Carinthia.

Bürg began his practical astronomical observations while still a university student. After his appointment as professor, he cooperated in, and was adviser to, the survey of Austria, but his main interest was calculation. He worked on the Viennese ephemerides for many years and was co-editor with Triesnecker.

Bürg was one of the leading calculating astronomers of his time, and his most important work was the recalculation of lunar ephemerides. He improved Laplace’s perturbation theory of the complicated motion of the moon by adding more terms of the perturbation function: for the influence of the sun - considered not as the central body but as a disturbing one - and for the oblateness of the earth. Thus he found in the secular motion of the moon a term with a period of about 180 years and an amount of 13.8". Taking this into consideration and making use of more recent observations, Bürg’s lunar ephemerides proved to be much more accurate than those of his predecessors. From 1813 to 1820 they formed the basis of the lunar ephemerides in the Nautical Almanach of the British Admiralty.

Achievements

• Johann Tobias Bürg is remembered as an astronomer, who developed a complex movement theory of the moon after analyzing more than 3000 observations of the moon, and discovered Antares as a binary star during its visual occultation observation.
  
  In 1834 the crater Bürg on the Moon was named by Johann Heinrich von Mädler in his honour.

Works

More photos

• book

  • Tables astronomiques 1806

Membership

Johann Tobias Bürg was made a member of the French Academy of Sciences, and the Russian Academy of Sciences.

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  Johann Bürg became a member of the Göttingen Academy of Sciences and Humanities in 1801.

  Göttingen Academy of Sciences and Humanities , Germany

  1801

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  Johann Tobias Bürg was elected a member of the Prussian Academy of Sciences (today it houses the Berlin State Library) in 1812.

  Prussian Academy of Sciences , Prussia

  1812

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  Johann Bürg became a member of the American Academy of Arts and Sciences in 1822.

  American Academy of Arts and Sciences , United States

  1822

Connections

Johann Tobias Bürg never married.

References

• Biographisches Lexikon Des Kaiserthums Oesterreich, Vol. 2
  1857
• Dictionary of Scientific Biography, Volume II
  1970