2nd Quarter Biography

Kenny Smith

Mr. Percival

Pd.00

8 Jan. 2010

Johann Franz Encke

Johann Franz Encke was born on September 23^rd, 1791 in Hamburg, Germany. Encke attended the University of Göttingen in 1811 and studied mathematics and astronomy under Carl Friedrich Gauss. Encke then enlisted in the military and did not return to the university until 1816. Almost immediately upon his return, Encke was appointed as an assistant at the Seeberg Observatory, near Gotha, Germany. In 1822, Encke was appointed director of the observatory. In 1823, he married Amalie Becker, with whom he had three sons and two daughters. In 1825, Encke took the position of professor of astronomy and director of the observatory at the University of Berlin. Encke worked for the University of Berlin until 1863. Encke later died on August 26^th, 1865.

While working at the Seeberg Observatory, Encke made many famous observations about comets. In 1817, Encke received the Cotta Prize for his work on the investigation of the comet of 1680. Encke also was able to figure out the orbital period of 71 years for the comet of 1812, which is now called 12P/Pons-Brooks. Perhaps his most famous discovery in regards to comets came when he examined the orbital elements of the comet of 1818 seen by Jean-Louis Pons. Pons suspected that one of the three comets observed during 1818 was the same comet that he had discovered in 1805. Encke calculated the orbital period to be about 3.3 years. Up until this point in history, all known comets had orbital periods of seventy years plus. Encke sent a note to Gauss explaining his findings and Gauss published the note. Encke became famous for being the discoverer of the short period comet. This comet was named Encke’s Comet in honor of Encke. This comet was one of the first comets named after someone other than its discoverer. In 1824, Encke received the Gold Medal from the Royal Astronomical Society in London because of his correct and ground-breaking prediction on the return of this comet in 1822. Encke also received this award in 1830.

While he was professor at the University of Berlin, Encke led and directed the preparation of the star-maps of the Berlin Academy. The maps were finished in 1859. Encke also spearheaded the building of a new observatory at the university. The new observatory was inaugurated in 1835. Encke was the teacher for many well known astronomers, including Johann Galle, who discovered Neptune while he was an assistant to Encke, F. F. E. Brünnow, B. A. Gould, K. N. A. Kruseger, W. J. Förster, Friedrich Tietjen, and K. C. Bruhns. Encke edited the Berliner Astronomisches Jahrbuch, which is an astronomical almanac that was issued every year from 1776 to 1960. Johann Encke also issued four volumes of the Astronomische Beobachtungen of the Berlin observatory and published several of his papers in Astronomische Nachrichten.

Encke has several other small contributions to the astronomical world. In 1837, he discovered a wide variation in the brightness of the A Ring of Saturn. When it was later discovered that this was caused by a gap between the A Ring and the very small F Ring, the gap was named the Encke Gap, even though Encke was not the true discoverer. Encke used observations from the transits of Venus that occurred in 1761 and 1769 to calculate the solar parallax to be 8.57 arc seconds, which is very close to today’s accepted value. Encke developed methods for calculating the orbits of minor planets and the orbits of double stars. Encke’s name has also been bestowed upon an asteroid, 9134 Encke, and a crater on the moon.

Johann Encke has had an immense impact on astronomy. His accurate investigations into comets made him famous around the world. Encke’s discovery of the short periodic comet sent shockwaves through the astronomical world. His star maps were used by his assistant, Johann Galle, to help discover Neptune. Encke impacted all aspects of the astronomy program at the University of Berlin and helped make the program one of the best around. Although not all of Encke’s contributions were obvious, he truly changed the world of astronomy as we know it today.

Sources:

"Encke, Johann Franz." Complete Dictionary of Scientific Biography. Vol. 4. Detroit: Charles Scribner's Sons, 2008. 369-370. Gale Virtual Reference Library. Gale. Sarasota County High. 8 Jan. 2010 .

"Johann Franz Encke." Encyclopædia Britannica. 2010. Encyclopædia Britannica Online. 08 Jan. 2010 <http://www.britannica.com/EBchecked/topic/186524/Johann-Franz-Encke>.

"Encke, Johann Franz (1791-1865)." Plichts Website. Ed. Chris Plicht. Web. 09 Jan. 2010. .

"Johann Franz Encke." -- jd --. Web. 08 Jan. 2010. .

"Johann Franz Encke." Cambridge Encyclopedia. Web. 09 Jan. 2010. .

"Johann Franz Encke." NNDB: Tracking the entire world. Web. 09 Jan. 2010. .