Johann Franz Encke (23 September 1791 – 26 August 1865) was a German astronomer, born in Hamburg. He is sometimes confused with Karl Ludwig Hencke, another German astronomer. Image File history File links Size of this preview: 448 × 599 pixel Image in higher resolution (634 × 848 pixel, file size: 446 KB, MIME type: image/jpeg) Johann Franz Encke (1791–1865), German astronomer. ... September 23 is the 266th day of the year (267th in leap years). ... 1791 (MDCCXCI) was a common year starting on Saturday (see link for calendar) of the Gregorian calendar (or a common year starting on Tuesday of the 11-day-slower Julian calendar). ... August 26 is the 238th day of the year in the Gregorian Calendar (239th in leap years). ... 1865 (MDCCCLXV) is a common year starting on Sunday. ... An astronomer or astrophysicist is a person whose area of interest is astronomy or astrophysics. ... Hamburg from above Hamburgs motto: May the posterity endeavour with dignity to conserve the freedom, which the forefathers acquired. ... Karl Ludwig Hencke (April 8, 1793 – September 25, 1866) was a German astronomer. ...

Encke studied mathematics and astronomy from 1811 at the University of Göttingen under Carl Friedrich Gauss; but he enlisted in the Hanseatic Legion for the campaign of 1813–1814, and became lieutenant of artillery in the Prussian service in 1815. Having returned to Göttingen in 1816, he was at once appointed by Bernhardt von Lindenau as his assistant in the observatory of Seeberg near Gotha. Euclid, Greek mathematician, 3rd century BC, as imagined by by Raphael in this detail from The School of Athens. ... A giant Hubble mosaic of the Crab Nebula, a supernova remnant Astronomy is the science of celestial objects (such as stars, planets, comets, and galaxies) and phenomena that originate outside the Earths atmosphere (such as auroras and cosmic background radiation). ... The Georg-August University of Göttingen (Georg-August-Universität Göttingen, often called the Georgia Augusta) was founded in 1734 by George II, King of Great Britain and Elector of Hanover, and opened in 1737. ...   (30 April 1777 – 23 February 1855) was a German mathematician and scientist of profound genius who contributed significantly to many fields, including number theory, analysis, differential geometry, geodesy, magnetism, astronomy and optics. ... The Livonian Order joined the Teutonic Order in 1237; the Monastic State of the Teutonic Order around 1455 After the partition of the 2nd Peace of Thorn in 1466 The Prussian Homage, Jan Matejko. ... Bernhard von Lindenau Baron Bernhard August von Lindenau (June 11, 1780 in Altenburg–May 21, 1854 in Altenburg) was a German lawyer, astronomer, minister, and art collector. ... Seeberg is a municipality in the district of Wangen, in the canton of Bern, Switzerland. ... Map of Germany showing Gotha Gotha is a town in the Land of Bundesland of Thuringia, in Germany. ...

There he completed his investigation of the comet of 1680, for which the Cotta prize was awarded to him in 1817; he correctly assigned a period of 71 years to the comet of 1812. That comet is now called 12P/Pons-Brooks. Comet Hale-Bopp Comet McNaught as seen from Swifts Creek, Victoria, Australia on 23 January 2007 A comet is a small body in the solar system that orbits the Sun and (at least occasionally) exhibits a coma (or atmosphere) and/or a tail â€” both primarily from the effects of... 1817 was a common year starting on Wednesday (see link for calendar). ... 12P/Pons-Brooks is the designation for a periodic comet with a period of 71 years. ...

Following a suggestion by Jean-Louis Pons, who suspected one of the three comets discovered in 1818 to be the same one already discovered by him in 1805, Encke began to calculate the orbital elements of this comet. At this time, all the known comets only had an orbital period of seventy years and more, where the aphelion is far beyond the orbit of Uranus. The most famous comet of this family was Comet Halley with its period of seventy-six years. Therefore the orbit of the comet discovered by Pons was a sensation, because his orbit was found to have a period of 3.3 years, therefore the aphelion had to be within the orbit of Jupiter. Encke predicted its return for 1822, but this return was only observable from the southern hemisphere and was seen by Carl Ludwig Christian Rümker from Australia. The comet was also identified with the one seen by Pierre Méchain in 1786 and by Caroline Herschel in 1795. Jean-Louis Pons (December 24, 1761 – October 14, 1831) was a French astronomer. ... The elements of an orbit are the parameters needed to specify that orbit uniquely, given a model of two ideal masses obeying the Newtonian laws of motion and the inverse-square law of gravitational attraction. ... The orbital period is the time it takes a planet (or another object) to make one full orbit. ... This article is about several astronomical terms (apogee & perigee, aphelion & perihelion, generic equivalents based on apsis, and related but rarer terms. ... Atmospheric characteristics Atmospheric pressure 120 kPa Hydrogen 83% Helium 15% Methane 1. ... Comet Halley, officially designated 1P/Halley, more generally known as Halleys Comet after Edmond Halley, is a comet that can be seen every 75-76 years. ... Atmospheric characteristics Atmospheric pressure 70 kPa Hydrogen ~86% Helium ~14% Methane 0. ... 1822 (MDCCCXXII) was a common year starting on Tuesday (see link for calendar) of the Gregorian calendar (or a common year starting on Thursday of the 12-day-slower Julian calendar). ... Carl Ludwig Christian Rümker (1788-1862), German astronomer, was born in Mecklenburg on 28 May 1788. ... Pierre François André Méchain (August 16, 1744 – September 20, 1804) was a French astronomer. ... Caroline Lucretia Herschel Caroline Lucretia Herschel (March 16, 1750 – January 9, 1848) was a German-born English astronomer. ...

Encke sent his calculations as a note to Gauss, Olbers, and Bessel. His former mathematics professor published this note and Encke became famous as the discoverer of the short periodic comets. The first object of this family, the Encke comet, was named after him and so it is one of the few comets not named after the discoverer, but after the one who calculated the orbit. Later this comet was identified as the origin of the Taurids meteor showers. Categories: Astronomers stubs | 1758 births | 1840 deaths | German astronomers | German physicists | Lists of asteroids ... Friedrich Wilhelm Bessel (July 22, 1784 – March 17, 1846) was a German mathematician, astronomer, and systematizer of the Bessel functions (which, despite their name, were discovered by Daniel Bernoulli). ... Comet Encke (officially designated 2P/Encke) is a periodic comet, named after Johann Franz Encke, who through laborious study of its orbit and many calculations was able to link multiple observations in the years 1786, 1795, 1805 and 1818 to the same object. ... The Taurids are an annual meteor shower associated with the comet Encke. ... Leonid Meteor Shower A meteor shower, also known as a meteor storm, is a celestial event where a large number of meteors are seen within a very short period. ...

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 a bookseller. They had three sons and two daughters. The Royal Astronomical Society (RAS) began as the Astronomical Society of London in 1820 to support astronomical research (mainly carried on at the time by gentleman astronomers rather than professionals). ... This article is about the capital of England and the United Kingdom. ... Gold Medal awarded to Asaph Hall The Gold Medal is the highest award of the Royal Astronomical Society. ... A bookstore. ...

Eight masterly treatises on its movements were published by him in the Berlin Abhandlungen (1829–1859). From a fresh discussion of the transits of Venus in 1761 and 1769 he deduced (1822–1824) a solar parallax of 8.57 arcsecond, long accepted as authoritative. The 2004 transit of Venus A transit of Venus across the Sun takes place when the planet Venus passes directly between the Sun and the Earth, obscuring a small portion of the Suns disc. ... This does not adequately cite its references or sources. ... A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ...

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 the Prussian king Friedrich Wilhelm III, was inaugurated in 1835. Encke became director of the new observatory. Seeberg is a municipality in the district of Wangen, in the canton of Bern, Switzerland. ... Berlin is the capital city and one of the sixteen states of the Federal Republic of Germany. ... An 1859 portrait of Alexander von Humboldt by the artist Julius Schrader, showing Mount Chimborazo in the background. ... Frederick William III Frederick William III, known in German as Friedrich Wilhelm III, reigned as king of Prussia from 1797 to 1840. ... | Come and take it, slogan of the Texas Revolution 1835 was a common year starting on Thursday (see link for calendar). ...

He directed the preparation of the star-maps of the Berlin Academy (1830–1859), edited from 1830 and greatly improved the Astronomisches Jahrbuch, and issued four volumes of the Astronomische Beobachtungen of the Berlin observatory (1840–1857). Within the following time Encke was involved in the discovery and orbital parameter determination of other short periodic comets and asteroids. In 1837 Encke discovered a gap of about 325 kilometers within the A ring of Saturn, the so called Encke division. Asteroids is a popular vector-based video arcade game released in 1979 by Atari. ... A planetary ring is a ring of dust and other small particles orbiting around a planet in a flat disc-shaped region. ... Atmospheric characteristics Atmospheric pressure 140 kPa Hydrogen >93% Helium >5% Methane 0. ... The Encke Division in closeup The Encke Division, also called the Encke Gap, is a perceived gap within Saturns A Ring. ...

In 1844, Encke became university professor for astronomy in Berlin. Much labor 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). Two bodies with similar mass orbiting around a common barycenter with elliptic orbits. ...

Encke visited England in 1840. Incipient brain-disease compelled him to withdraw from official life in November 1863. He still was director of the Berlin observatory until his death on 26 August 1865 in Spandau. His successor was Wilhelm Julius Foerster (1832–1921). Motto: (French for God and my right) Anthem: God Save the King/Queen Capital London (de facto) Largest city London Official language(s) English (de facto) Unification    - by Athelstan AD 927  Area    - Total 130,395 km² (1st in UK)   50,346 sq mi  Population    - 2006 est. ... August 26 is the 238th day of the year in the Gregorian Calendar (239th in leap years). ... 1865 (MDCCCLXV) is a common year starting on Sunday. ... For the 1980s New Wave group, see Spandau Ballet. ... Wilhelm Julius Förster (December 16, 1832 – January 18, 1921) was a German astronomer, father of the pacifist and ethicist Friedrich Wilhelm Förster. ...

He contributed extensively to the periodical literature of astronomy.

Encke is buried at a cemetery in the Kreuzberg section of Berlin, the Friedhof II der Jerusalems- und Neuen Kirchengemeinde (61 Baruther Street). His grave is close to that Carl Gustav Jacob Jacobi, the mathematician. Karl Gustav Jacob Jacobi (Potsdam December 10, 1804 - Berlin February 18, 1851), was not only a great German mathematician but also considered by many as the most inspiring teacher of his time (Bell, p. ...

Honors

• Twice, in 1824 and 1830, the recipient of the Gold Medal of the Royal Astronomical Society.
• Encke crater on the Moon is named for him.
• The asteroid 9134 Encke is named in his honour.

Gold Medal awarded to Asaph Hall The Gold Medal is the highest award of the Royal Astronomical Society. ... Encke is a lunar crater that is located on the western edge of the Mare Insularum, to the south-southeast of the Kepler crater. ... Apparent magnitude: up to -12. ... 253 Mathilde, a C-type asteroid. ...

References

See Johann Franz Encke, sein Leben und Wirken, von Dr C. Bruhns (Leipzig, 1869), to which a list of his writings is appended. Also, Month. Notices Roy. Astr. Society, xxvi. 129; V.J.S. Astr. Gesellschaft, iv. 227; Berlin Abkandlungen (1866), LG Hagen; Sitzungsberichte, Munich Acad. (1866), i. p. 395, etc.

External links

• Obituary of "John Francis Encke"

This article incorporates text from the Encyclopædia Britannica Eleventh Edition, a publication now in the public domain. Encyclopædia Britannica, the 11th edition The Encyclopædia Britannica Eleventh Edition (1910–1911) is perhaps the most famous edition of the Encyclopædia Britannica. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...