astronomy

Østervold Observatory

Østervold Observatory is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Østervold Observatory rather than just read about it. In short: Østervold Observatory (or Copenhagen University Observatory; Danish: Københavns Universitet Astronomisk Observatorium) is a former astronomical observatory (IAU code 035) in Copenhagen, Denmark owned and operated by the University of Copenhagen (Københavns Universitet). It opened in 1861 as a replacement for the university's old observatory at Rundetårn.

Key takeaways

Østervold Observatory belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Østervold Observatory to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Østervold Observatory from memory before moving on to harder problems.

Reference excerpt

Østervold Observatory (or Copenhagen University Observatory; Danish: Københavns Universitet Astronomisk Observatorium) is a former astronomical observatory (IAU code 035) in Copenhagen, Denmark owned and operated by the University of Copenhagen (Københavns Universitet). It opened in 1861 as a replacement for the university's old observatory at Rundetårn. The Østervold Observatory building house the Institute for Science Didactics of the University of Copenhagen.

History The first astronomical observatory operated by the University of Copenhagen was Rundetårn. It had been inaugurated in 1642 as a replacement for Tycho Brahe's Stjerneborg, but during the early 19th century had become outdated as astronomical instruments grew bigger and bigger while the tower could not be expanded. In the same time, light pollution from the surrounding city as well as vibrations caused by the still increasing traffic in the streets below had made the observations inaccurate.

In 1861 the observatory was moved to Østervold, where a new observatory was constructed on the old bastioned fortifications of the city, which had become outdated and were being abandoned. The well-known Russian-German astronomer, Heinrich Louis d'Arrest, who had been appointed professor in astronomy at the university in 1857, was chosen to plan the new observatory. He used the observatory for his study of nebulas, in 1867 publishing an astronomical catalogue of 1,942 nebulas with 4,900 positions. He also did significant work in spectroscopy, and discovered, for the first time, the differences in the evolutionary state and spatial distribution of stars. While d'Arrest used the main telescope, observer H. C. F. C. Schjellerup used the Meridian circle for creating one of the most comprehensive astronomical catalogues of the time of stars of the 8th-9th magnitude: 10,000 positions on 259 observation nights. The next director of the Østervold Observatory was Thorvald N. Thiele, a skilful mathematician who developed a new method of determining the orbit of Binary stars. He founded the tradition for numerical computational mathematics, which has lasted up to modern times. In 1907, Elis Strömgren was appointed professor and director of the observatory, and under his direction the computational work continued.

During World War I, the Central Bureau for Astronomical Telegrams, founded by Astronomische Gesellschaft in 1882, was moved from Kiel, Germany, to the Østervold Observatory. It remained located in Copenhagen until 1965, when it was moved to the Smithsonian Astrophysical Observatory, Cambridge, United States. In 1940 Ellis Strömgren was succeeded by his son Bengt Strömgren, who made the pioneering discovery that hydrogen is the most abundant element in the stellar interior. He was also the first to make the correct interpretation of the Hertzsprung–Russell diagram (the relation between the total energy output from a star and its surface temperature was independently found by the Danish chemist and astronomer Ejnar Hertzsprung and the American astronomer Henry Norris Russell). Around 1950, he developed the uvbyß photoelectric system, which is still in use today. In the 1950s, the Østervold Observatory was replaced by the Brorfelde Observatory located near the town of Holbæk, which was provided with a very fine meridian circle and a Schmidt telescope with a camera that used photographic film. It houses a 300 double reflector with a focal depth of 4.9m.

Building

The Østervold Observatory is a south-facing, three-winged building, designed by Christian Hansen. The central wing is topped by a dome. containing the main instrument. The side wings contained residences for the director, the observer as well as assistants. To secure the best possible foundation of the instruments, the foundation of the building rests on the original, true ground surface, penetrating the entire depth of the ramparts on which the building stands. This took 1/3 of the bricks used for the entire complex. The Østervold Observatory building is no longer used for astronomy, but it was often used among ornithologists. The buildings house the Institute for Science Didactics University of Copenhagen.

Instruments The original main instrument of the observatory, housed in the dome, was a 280 mm refractor with a focal distance of 4.9 m. In 1895, this telescope was replaced by a 360 mm refractor with a focal length of 4.9 m and a 200 mm photographic lens with a focal length of 4.8 m. The purchase of the double refractor enabled the observatory to participate in photographic observations without having to give up visual observations. This double refractor is still found in the dome of the Østervold Observatory, while the 1861 refractor is displayed at the Steno Museum in Århus. c

Directors 1862-1875: Heinrich Louis d'Arrest 1875-1907: Thorvald N. Thiele 1907-1940: Elis Strömgren 1940–1951. Bengt Strömgren

See also Brorfelde Observatory List of astronomical observatories Rundetårn

References

External links

History of Copenhagen University Observatory Coords

Illustrations

Østervold Observatory: Østervold ObservatoryWium — Østervold ObservatoryWium

Worked examples

Example 1 — a first encounter with Østervold Observatory

Start with the simplest possible case. Write down what Østervold Observatory claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Østervold Observatory before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Østervold Observatory ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Østervold Observatory

In research: Østervold Observatory appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Østervold Observatory in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Østervold Observatory is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1861 establishments in Denmark, Astronomical observatories in Denmark, Buildings and structures in Copenhagen parks, so understanding it makes those chapters shorter.
In everyday life: Look for Østervold Observatory outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Østervold Observatory in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Østervold Observatory means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Østervold Observatory out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Østervold Observatory in simple terms?

Why does Østervold Observatory matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Østervold Observatory?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Østervold Observatory.