Karl Ludwig Hencke (8 April 1793 – 21 September 1866) was a German

amateur astronomer Amateur astronomy is a hobby where participants enjoy observing or imaging celestial objects in the sky using the unaided eye, binoculars, or telescopes. Even though scientific research may not be their primary goal, some amateur astronomers ...

and discoverer of

minor planet According to the International Astronomical Union (IAU), a minor planet is an astronomical object in direct orbit around the Sun that is exclusively classified as neither a planet nor a comet. Before 2006, the IAU officially used the term ''mino ...

s. He is sometimes confused with

Johann Franz Encke Johann Franz Encke (; 23 September 179126 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 ...

, another German astronomer.

Biography

Hencke was born in Driesen,

Brandenburg Brandenburg (; nds, Brannenborg; dsb, Bramborska ) is a state in the northeast of Germany bordering the states of Mecklenburg-Vorpommern, Lower Saxony, Saxony-Anhalt, and Saxony, as well as the country of Poland. With an area of 29,480 square ...

(now

Drezdenko Drezdenko (; german: Driesen) is a town in western Poland, in Lubusz Voivodeship, in Strzelce-Drezdenko County. As of December 2021, the town has a population of 9,804. History The area was a site of a border fort of the medieval Polish state. ...

, Poland). He volunteered in the Wars of Liberation (''Befreiungskriege'') for

Prussia Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was '' de facto'' dissolved by an ...

but was wounded at

Lützen is a town in the Burgenlandkreis district of Saxony-Anhalt, Germany. Geography Lützen is situated in the Leipzig Bay, approximately southwest of the Leipzig city limits and northeast of Weißenfels. The town has access to the Bundesstraße ...

. Thereafter he served as post official at various places and finally was erected post master. After his retirement at age 45 for health reasons he lived in his city of birth where he served as city court judge. He discovered two

asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere ...

s from his private observatory at #9, Kietz (now #43, Kietzerstraße), Driesen, by comparing star maps with the sky seen through his telescope. The first,

5 Astraea Astraea () (minor planet designation: 5 Astraea) is an asteroid in the asteroid belt. Its surface is highly reflective and its composition is probably a mixture of nickel–iron with silicates of magnesium and iron. It is an S-type asteroid in ...

, was the first asteroid discovered after the long gap that followed the last of the original four,

4 Vesta Vesta (minor-planet designation: 4 Vesta) is one of the largest objects in the asteroid belt, with a mean diameter of . It was discovered by the German astronomer Heinrich Wilhelm Matthias Olbers on 29 March 1807 and is named after Vesta, the ...

, which was discovered already in 1807. Other astronomers had abandoned their searches for more asteroids, convinced that there were only four. However, Hencke began searching in 1830, and fifteen years later met with success. Two years later he discovered his second asteroid

6 Hebe Hebe ( minor planet designation: 6 Hebe) is a large main-belt asteroid, containing around 0.5% of the mass of the belt. However, due to its apparently high bulk density (greater than that of the Moon or even Mars), Hebe does not rank among the ...

. He also worked on the improvement of star maps. He died at the age of 73 in the northern Polish town of

Kwidzyn Kwidzyn (pronounced ; german: Marienwerder; Latin: ''Quedin''; Old Prussian: ''Kwēdina'') is a town in northern Poland on the Liwa River, with 38,553 inhabitants (2018). It is the capital of Kwidzyn County in the Pomeranian Voivodeship. Geog ...

, what was then called ''Marienwerder'' and part of Prussia. The asteroid 2005 Hencke – a main-belt asteroid of the

Eunomia family The Eunomia or Eunomian family () is a large asteroid family of S-type asteroids named after the asteroid 15 Eunomia. It is the most prominent family in the intermediate asteroid belt and the 6th-largest family with nearly six thousand known member ...

, discovered by Swiss astronomer Paul Wild in 1973, was named in his memory ().

References

External links

Biography search
at www.deutsche-biographie.de

– from Nordisk familjebok by Projekt Runeberg (in Swedish) {{DEFAULTSORT:Hencke, Karl Ludwig 1793 births 1866 deaths Discoverers of asteroids 19th-century German astronomers People from Drezdenko People from the Margraviate of Brandenburg People from Kwidzyn Recipients of the Lalande Prize