Franz Xaver von Zach | |
|---|---|
 | |
| Born | (1754-06-04)4 June 1754 |
| Died | 2 September 1832(1832-09-02) (aged 78) Paris |
| Scientific career | |
| Fields | astronomy |
BaronFranz Xaver von Zach (Franz XaverFreiherr von Zach; 4 June 1754 – 2 September 1832) was an Austrian astronomer born atPest, Hungary (nowBudapest in Hungary).
Zach studied physics at theRoyal University of Pest, and served for some time in the Austrian army. He taught at theUniversity of Lemberg (nowLviv, Ukraine) and worked in its observatory.[1] He lived in Paris in 1780–83, and in London from 1783 to 1786 as tutor in the house of theSaxon ambassador,Hans Moritz von Brühl. In Paris and London he entered the circles of astronomers likeJérôme Lalande,Pierre-Simon Laplace andWilliam Herschel. In 1786 he was appointed byErnest II, Duke of Saxe-Gotha-Altenburg director of the newobservatory on Seeberg hill atGotha, which was finished in 1791. At the close of the 18th century, he organised thefirst European congress of astronomers in 1798 and established the "celestial police", a group of twenty-four astronomers, to prepare for a systematic search for the "missing planet" predicted by theTitius–Bode law betweenMars andJupiter.Ceres was discovered by accident just as the search was getting underway. Using predictions made of the position of Ceres byCarl Friedrich Gauss, on 31 December 1801/1 January 1802, Zach (and, independently one night later,Heinrich Wilhelm Matthias Olbers) recovered Ceres after it was lost during its passage behind the Sun. After the death of the duke in 1804, Zach accompanied the duke's widow on her travels in the south of Europe, and the two settled inGenoa in 1815 where he directed an observatory. He moved back to Paris in 1827 and died there in 1832.[2]
Zach publishedTables of the Sun (Gotha, 1792; new and improved edition, Gotha, 1804), and numerous papers on geographical subjects, particularly on the geographical positions of many towns and places, which he determined on his travels with asextant.[2]
His principal importance was, however, as editor of three scientific journals of great value:Allgemeine Geographische Ephemeriden (4 vols., Gotha, 1798–1799),Monatliche Correspondenz zur Beförderung der Erd- und Himmels-Kunde (28 vols., Gotha, 1800–1813, from 1807 edited byBernhard von Lindenau), andCorrespondance astronomique, geographique, hydrographique, et statistique (Genoa, 1818–1826, 14 vols., and one number of the 15th, the suppression of which was instigated by theJesuits).[2]
He was elected as a member of theRoyal Swedish Academy of Sciences in 1794, a Foreign Honorary Member of theAmerican Academy of Arts and Sciences in 1798,[3] a Fellow of theRoyal Society in 1804, and an honorary member of theHungarian Academy of Sciences in 1832.
In 1808, von Zach was inMarseille where he observed and explained the phenomenon of theCanigou mountain in easternPyrénées which can be seen twice a year from there, 250 km away, by refraction of light.[4]
Asteroid999 Zachia and the craterZach on the Moon are named after him, while asteroid64 Angelina is named after an astronomical station he set up nearMarseille.
One or more of the preceding sentences incorporates text from a publication now in thepublic domain: Chisholm, Hugh, ed. (1911). "Zach, Franz Xaver, Baron von".Encyclopædia Britannica. Vol. 28 (11th ed.). Cambridge University Press. p. 949.
