The Sternwarte Düsseldorf (a.k.a. Sternwarte Bilk, Sternwarte Charlottenruhe; Bilk Observatory or Düsseldorf-Bilk Observatory in English) in

Düsseldorf-Bilk Bilk is a quarter (''Stadtteil'') of Düsseldorf. Together with Düsseldorf-Oberbilk, Oberbilk, Düsseldorf-Unterbilk, Unterbilk, Düsseldorf-Hamm, Hamm, Düsseldorf-Flehe, Flehe and Volmerswerth it constitutes Borough 3 (Düsseldorf), Borough 3, ...

was a private observatory founded in 1843 by

Johann Friedrich Benzenberg Johann Friedrich Benzenberg (5 May 1777 – 7 June 1846) was a German astronomer, geologist, and physicist. Biography Benzenberg was born near Elberfeld, Germany on 5 May 1777 to Heinrich Benzenberg and Johanna Elisabeth. He married Charlotte Pla ...

. The observatory's main feature was a refracting telescope with 1800mm

focal length The focal length of an optical system is a measure of how strongly the system converges or diverges light; it is the inverse of the system's optical power. A positive focal length indicates that a system converges light, while a negative foca ...

. After Benzenberg's death the

observatory An observatory is a location used for observing terrestrial, marine, or celestial events. Astronomy, climatology/meteorology, geophysical, oceanography and volcanology are examples of disciplines for which observatories have been constructed. His ...

was bequeathed to the city of Düsseldorf. It was destroyed by bombing in 1943. Between 1852 and 1890,

C. Robert Luther Karl Theodor Robert Luther (April 16, 1822, Świdnica – February 15, 1900 Düsseldorf), normally published as Robert Luther, was a German astronomer. While working at the Bilk Observatory in Düsseldorf, Germany, he searched for asteroids and d ...

discovered 24

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 there, from Thetis, discovered on April 17, 1852, to Glauke, discovered February 20, 1890. These asteroids and

planetoid 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 are called ''the 24 Düsseldorf planets''. The asteroid 4425 Bilk is named in honour of the observatory. Near its original location, a benchmark was erected, displaying the observatory's burnt-out telescope. File:bst-close.jpg, Benchmark File:bst-durch.jpg, view through the tube File:bst-dist.jpg, front view File:bst-schild.jpg, information plate

References

Astronomical observatories in Germany Buildings and structures in Düsseldorf Tourist attractions in Düsseldorf {{observatory-stub

See also

References