Johann Franz Encke
Johann Franz Encke | |
---|---|
12P/Pons-Brooks comet | |
Awards | Cotta prize (1817) Royal Medal (1828) Gold Medal of the Royal Astronomical Society (1824, 1830) |
Scientific career | |
Fields | Astronomy |
Institutions | University of Berlin |
Academic advisors | Carl Friedrich Gauss |
Doctoral students | Johann Gottfried Galle Leopold Kronecker Demetrios Kokkidis |
Johann Franz Encke (German pronunciation: [ˈjoːhan ˈfʁants ˈɛŋkə]; 23 September 1791 – 26 August 1865) was a German astronomer. Among his activities, he worked on the calculation of the periods of comets and asteroids, measured the distance from the Earth to the Sun, and made observations of the planet Saturn.
Biography
Encke was born in
Having returned to Göttingen in 1816, he was at once appointed by
Following a suggestion by
Encke sent his calculations as a note to Gauss, Olbers, and
The importance of the predicted return based on the calculation by Encke was rewarded by the Royal Astronomical Society in London by presenting their Gold Medal to him in 1824. In this year Encke married Amalie Becker (1787–1879), daughter of author, bookseller and publisher Rudolph Zacharias Becker, the publisher of works from the Seeberg Observatory. They had three sons and two daughters. In 1825 he was elected a Fellow of the Royal Society.[2]
Eight masterly treatises on the comet's movements were published by him in the Berliner Abhandlungen (1829–1859). From a fresh discussion of the
In 1822 he became director of the Seeberg observatory, and in 1825 was promoted to a corresponding position at Berlin, where a new observatory, built under his superintendence and with the support of Alexander von Humboldt and King Frederick William III of Prussia, was inaugurated in 1835.[1] Mostly on the recommendation of Bessel, Encke became director of the new observatory and secretary of the Academy of Sciences.
He directed the preparation of the star maps of the Academy (1830–1859); beginning in 1830, he edited and greatly improved the Astronomisches Jahrbuch; and he issued four volumes of the Astronomische Beobachtungen auf der Sternwarte zu Berlin (Observations of the Berlin observatory, 1840–1857).
In 1837, Encke described a broad variation in the brightness of the A Ring of Saturn. The Encke Gap was later named in honour of his observations of Saturn's rings.
In 1844, Encke became professor of astronomy at the University of Berlin. Much labour was bestowed by him upon facilitating the computation of the movements of the asteroids. With this end in view he expounded to the Berlin Academy in 1849 a mode of determining an elliptic orbit from three observations, and communicated to that body in 1851 a new method of calculating planetary perturbations by means of rectangular coordinates (republished in W. Ostwald's Klassiker der exacten Wissenschaften, No. 141, 1903).[1]
Encke visited England in 1840. He was elected a foreign member of the Royal Swedish Academy of Sciences in 1836, a member to the American Philosophical Society in 1839,[3] and a Foreign Honorary Member of the American Academy of Arts and Sciences in 1849.[4] Incipient brain-disease compelled him to withdraw from official life in November 1863.[1] He still was director of the Berlin observatory until his death on 26 August 1865 in Spandau. His successor was Wilhelm Julius Foerster.
He contributed extensively to the periodical literature of astronomy.[1]
Encke's grave is preserved at a cemetery in the
Honors
- Twice, in 1824 and 1830, the recipient of the Gold Medal of the Royal Astronomical Society.[1]
- The crater Encke on the Moon is named after him.
- 9134 Enckeis named in his honour.
- The Encke gap of Saturn's rings is named after him.
- Comet Encke is named after him for his calculation of its orbit.
Notes
This article includes a list of general references, but it lacks sufficient corresponding inline citations. (October 2019) |
- ^ a b c d e f g h i public domain: Clerke, Agnes Mary (1911). "Encke, Johann Franz". In Chisholm, Hugh (ed.). Encyclopædia Britannica. Vol. 9 (11th ed.). Cambridge University Press. p. 369. One or more of the preceding sentences incorporates text from a publication now in the
- ^ "Library and Archive Catalogue". Royal Society. Retrieved 30 November 2010.[permanent dead link]
- ^ "APS Member History". search.amphilsoc.org. Retrieved 9 April 2021.
- ^ "Book of Members, 1780–2010: Chapter E" (PDF). American Academy of Arts and Sciences. Retrieved 15 September 2016.
References
- New International Encyclopedia(1st ed.). New York: Dodd, Mead.