Theodor Brorsen
Encyclopedia
Astronomer
An astronomer is a scientist who studies celestial bodies such as planets, stars and galaxies.Historically, astronomy was more concerned with the classification and description of phenomena in the sky, while astrophysics attempted to explain these phenomena and the differences between them using...
best known for his discovery of five comet
Comet
A comet is an icy small Solar System body that, when close enough to the Sun, displays a visible coma and sometimes also a tail. These phenomena are both due to the effects of solar radiation and the solar wind upon the nucleus of the comet...
s, including the lost periodic comet 5D/Brorsen
5D/Brorsen
5D/Brorsen is a comet discovered February 26, 1846, by the Danish astronomer Theodor Brorsen....
and the periodic comet 23P/Brorsen-Metcalf
23P/Brorsen-Metcalf
Comet Brorsen–Metcalf is a periodic comet in our solar system that was first discovered by Theodor Brorsen on July 20, 1847, and again by Kaspar Schweizer on August 11, 1847, the prediction was made it would return between 1919 and 1922.On August 21, 1919, the comet was recovered by Reverend Joel...
.
Life
Theodor Johan Christian Ambders Brorsen was born in NordborgNordborg
Nordborg , is a town with a population of 6,730 and a former municipality in Sønderborg Municipality, Region of Southern Denmark on the northwest half of the island of Als off the east coast of the Jutland peninsula in south Denmark. The former Nordborg municipality covered an area of...
on the island Als (South Jutland) as son of the captain Christian August Brorsen (1793-1840) and his wife Annette Margrethe Gerhardine Schumacher (1788-1855). He got his three middle names after the maternal grandfather of his mother, the Nordborg counsel Johan Christian Ambders (1710-1795). After the amicable divorce of his parents in 1822, Brorsen grew up at his mother’s. Her good financial circumstances allowed him to attend the school of the Moravians in Christiansfeld
Christiansfeld
Christiansfeld, with a population of 2,915 , is a town in Kolding Municipality in Southern Jutland in Region of Southern Denmark in Denmark....
(1826-1829) and then (1830-1839) the Latin school in Flensburg
Flensburg
Flensburg is an independent town in the north of the German state of Schleswig-Holstein. Flensburg is the centre of the region of Southern Schleswig...
. By request of his mother, Brorsen studied law in Kiel
Kiel
Kiel is the capital and most populous city in the northern German state of Schleswig-Holstein, with a population of 238,049 .Kiel is approximately north of Hamburg. Due to its geographic location in the north of Germany, the southeast of the Jutland peninsula, and the southwestern shore of the...
(1839), Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...
(1840), Heidelberg
Heidelberg
-Early history:Between 600,000 and 200,000 years ago, "Heidelberg Man" died at nearby Mauer. His jaw bone was discovered in 1907; with scientific dating, his remains were determined to be the earliest evidence of human life in Europe. In the 5th century BC, a Celtic fortress of refuge and place of...
(1841) and again in Kiel (1842), until he decided to follow his inclinations and studied astronomy in Kiel since 1844.
Brorsen worked at the astronomical observatory of Kiel (1846) and of Altona, Hamburg
Altona, Hamburg
Altona is the westernmost urban borough of the German city state of Hamburg, on the right bank of the Elbe river. From 1640 to 1864 Altona was under the administration of the Danish monarchy. Altona was an independent city until 1937...
(1847). He rejected a job offer from the astronomical oberservatory "Rundetaarn" (Round tower) in Copenhagen
Copenhagen
Copenhagen is the capital and largest city of Denmark, with an urban population of 1,199,224 and a metropolitan population of 1,930,260 . With the completion of the transnational Øresund Bridge in 2000, Copenhagen has become the centre of the increasingly integrating Øresund Region...
. Instead, he accepted a job at the private observatory of baron John Parish (1774-1858, an Englishman, also known as Freiherr von Senftenberg) in Žamberk
Žamberk
Žamberk is a town in the Pardubice Region of the Czech Republic. It has about 6,100 inhabitants.-Museums and Historic Sites:* Municipal Museum – Československé armády 472* House of Prokop Diviš – Helvíkovice 326* Litice - ancient castle...
(at the time called Senftenberg) in the present-day Czech Republic
Czech Republic
The Czech Republic is a landlocked country in Central Europe. The country is bordered by Poland to the northeast, Slovakia to the east, Austria to the south, and Germany to the west and northwest....
. When the post of the director of the astronomical observatory of Altona became vacant in 1854, Brorsen applied to it, but was not chosen. After the death of baron Parish in 1858, his heirs had the observatory of Senftenberg dismantled and the astronomical instruments sold although Brorsen offered to continue his work for free. Nevertheless Brorsen remained twelve further years in Senftenberg and continued his observations with his own instruments.
In 1870, he returned to his home town Nordborg in South Jutland, which had become Prussian since the Second War of Schleswig
Second War of Schleswig
The Second Schleswig War was the second military conflict as a result of the Schleswig-Holstein Question. It began on 1 February 1864, when Prussian forces crossed the border into Schleswig.Denmark fought Prussia and Austria...
of 1864 and subsequently was German from 1871 up to the plesbiscite of 1920. In 1874, Brorsen moved into the house Løjtertoft 11, where he lived until his death. His unmarried half sister Amalie Petrine Brorsen (1832-1911) kept house for him. In his years in Nordborg, however, Brorsen hardly occupied himself with astronomy any more. His main interests were meteorology
Meteorology
Meteorology is the interdisciplinary scientific study of the atmosphere. Studies in the field stretch back millennia, though significant progress in meteorology did not occur until the 18th century. The 19th century saw breakthroughs occur after observing networks developed across several countries...
(also observations of Northern Lights
Aurora (astronomy)
An aurora is a natural light display in the sky particularly in the high latitude regions, caused by the collision of energetic charged particles with atoms in the high altitude atmosphere...
) as well as botany
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...
, especially orchid breeding.
Personally, Brorsen was an introverted character with relationship anxieties. He twice broke off an engagement in the last moment (first one to Louise Lassen from Sønderborg, then another one to Miss Bernkopf from Žamberk) and hence remained unmarried. Besides, there are testimonies that Brorsen developed self-willed habits in the last 25 years of his life spent in Nordborg. He did not take much care for his clothing, he let his hair grow long, and when his boots pressed his feet, he cut holes into his boots in the tight places. He used to take a daily bath in the Oldenor, a lake in Nordborg; in winter, he hoed a hole into the ice for that purpose. Brorsen died at 75 years of age and was buried on April 5, 1895, in the cemetery of Nordborg where his grave is still preserved today.
Discoveries
- Brorsen discovered five comets: 1846 III, 1846 VII, 1847 V, 1851 III and 1851 IV. Two of them were named after Brorsen as they are periodic comets. The comet 1846 III is called Brorsen and the comet 1847 V is named Brorsen-Metcalf (because Joel Hastings MetcalfJoel Hastings MetcalfJoel Hastings Metcalf was an American astronomer.Metcalf graduated from Harvard Divinity School in 1892. He served as a Unitarian minister in Burlington, Vermont and then later in Taunton, Massachusetts, Winchester, Massachusetts and Portland, Maine.He discovered or co-discovered several comets,...
was its rediscoverer in 1919).
- The comet 5D/Brorsen5D/Brorsen5D/Brorsen is a comet discovered February 26, 1846, by the Danish astronomer Theodor Brorsen....
(with a period of 5.46 years) was last seen in 1879. In all, five of its rotations around the sun were observed. It belonged to the Jupiter comet family, whose comets can be short-lived so it may not exist any longer today.
- The comet 23P/Brorsen-Metcalf23P/Brorsen-MetcalfComet Brorsen–Metcalf is a periodic comet in our solar system that was first discovered by Theodor Brorsen on July 20, 1847, and again by Kaspar Schweizer on August 11, 1847, the prediction was made it would return between 1919 and 1922.On August 21, 1919, the comet was recovered by Reverend Joel...
(with a period of 69.06 years) was observed in 1847, 1919 and 1989. It belongs to the Halley comet family and is to be expected for 2059 again.
- In 1850, Brorsen (re-)discovered an emission nebulaEmission nebulaAn emission nebula is a cloud of ionized gas emitting light of various colors. The most common source of ionization is high-energy photons emitted from a nearby hot star...
in the constellation OrionOrion (constellation)Orion, often referred to as The Hunter, is a prominent constellation located on the celestial equator and visible throughout the world. It is one of the most conspicuous, and most recognizable constellations in the night sky...
, NGC 2024, also known as Flame NebulaFlame NebulaThe Flame Nebula, designated as NGC 2024 and Sh2-277, is an emission nebula in the constellation Orion. It is about 900 to 1,500 light-years away....
, which had already been observed, however, by William HerschelWilliam HerschelSir Frederick William Herschel, KH, FRS, German: Friedrich Wilhelm Herschel was a German-born British astronomer, technical expert, and composer. Born in Hanover, Wilhelm first followed his father into the Military Band of Hanover, but emigrated to Britain at age 19...
in 1786, as we know today.
- Brorsen might have discovered a sixth comet on March 16, 1854; this discovery could not be confirmed by other astronomers, though.
- In 1854, Brorsen published the first thorough investigations of the so-called gegenscheinGegenscheinThe gegenschein is a faint brightening of the night sky in the region of the antisolar point.- Explanation :Like the zodiacal light, the gegenschein is sunlight reflected by interplanetary dust...
(counter shine) of the Zodiacal lightZodiacal lightZodiacal light is a faint, roughly triangular, whitish glow seen in the night sky which appears to extend up from the vicinity of the sun along the ecliptic or zodiac. Caused by sunlight scattered by space dust in the zodiacal cloud, it is so faint that either moonlight or light pollution renders...
. He was also able to explain that phenomenon correctly. Besides, Brorsen was the first to discover that the Zodiacal light can embrace the complete sky, because under favorable conditions, a feeble light bridge connecting the Zodiacal light and the counter glow can be observed.
- In 1856, Brorsen discovered a globular clusterGlobular clusterA globular cluster is a spherical collection of stars that orbits a galactic core as a satellite. Globular clusters are very tightly bound by gravity, which gives them their spherical shapes and relatively high stellar densities toward their centers. The name of this category of star cluster is...
in the constellation SerpensSerpensSerpens is a constellation of the northern hemisphere. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations defined by the International Astronomical Union....
, which was later catalogued as NGC 6539NGC 6539NGC 6539 is a globular cluster in the constellation Serpens. It was discovered by Theodor Brorsen in 1856....
.
- Further, Brorsen investigated the occultationOccultationAn occultation is an event that occurs when one object is hidden by another object that passes between it and the observer. The word is used in astronomy . It can also refer to any situation wherein an object in the foreground blocks from view an object in the background...
s and proper motionProper motionThe proper motion of a star is its angular change in position over time as seen from the center of mass of the solar system. It is measured in seconds of arc per year, arcsec/yr, where 3600 arcseconds equal one degree. This contrasts with radial velocity, which is the time rate of change in...
s of stars. In the field of theoretical astronomy, Brorsen calculated the periheliaApsisAn apsis , plural apsides , is the point of greatest or least distance of a body from one of the foci of its elliptical orbit. In modern celestial mechanics this focus is also the center of attraction, which is usually the center of mass of the system...
of comet and planet orbits.
Honors
- For each of his first three comet discoveries, Brorsen was rewarded a golden comet medal by the Danish king Christian VIII. The medal which he got in 1846 can be seen today in the museum at Sønderborg castle, see here.
- Brorsen was appointed a corresponding member of the nature historic society in Žamberk in 1850.
- In Nordborg, a street is named after Brorsen today (Th. Brorsens vej).
- The asteroidAsteroidAsteroids are a class of small Solar System bodies in orbit around the Sun. They have also been called planetoids, especially the larger ones...
39793979 Brorsen3979 Brorsen is a main-belt asteroid discovered on November 8, 1983 by Antonín Mrkos at Klet.On proposal of Jana Tichá, the comet was named Brorsen after the Danish astronomer Theodor Brorsen on August 8, 1996.- External links :*...
, which was discovered by A. MrkosAntonín MrkosAntonín Mrkos was a Czech astronomer, born in Střemchoví, Czechoslovakia.- Biography :Mrkos entered the University in Brno in 1938. His studies were interrupted by the onset of World War II, and in 1945 he became a staff member at the Skalnaté Pleso Observatory in Slovakia...
in Klet on November 8, 1983, was named "Brorsen" on proposal of J. TicháJana TicháJana Tichá is a Czech astronomer. She studied at the University of Economics in Prague and graduated in 1987. In 1992 she was selected for the position of a director of the Kleť Observatory. She specializes in discoveries of asteroids and comets especially Near-Earth objects...
(MPC 27734 – 1996 August 28).
Literature
- Sven Houmøller, Otto Kryck: Familien Brorsen fra Nordborg. Copenhagen 1949, p. 25-28 (listing the previous literature).
- Hertha Raben Petersen: Theodor Brorsen. Astronom. Nordborg 1986. ISBN 87-88558-053