astronomy

Pieter Oosterhoff

Pieter Oosterhoff 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 Pieter Oosterhoff rather than just read about it. In short: Pieter Theodorus Oosterhoff (30 March 1904, Leeuwarden - 14 March 1978, Leiden) was a Dutch astronomer. He was the co-administrator, along with Jan Oort, of the Leiden Observatory in the Netherlands.

Key takeaways

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

Reference excerpt

Pieter Theodorus Oosterhoff (30 March 1904, Leeuwarden - 14 March 1978, Leiden) was a Dutch astronomer. He was the co-administrator, along with Jan Oort, of the Leiden Observatory in the Netherlands. His published papers are primarily in regard to variable stars and photometry. He is most noted for his 1939 observation that there appear to be two populations of globular clusters based on the periodicities of their RR Lyrae variable stars. These two populations would come to be known as Oosterhoff groups after him. Between 1951 and 1952 he served as assistant general secretary of the International Astronomical Union, and served as general secretary from 1952 until 1958. In 1954 he was one of twelve European astronomers who drafted a statement that would lead to the formation of the ESO. The asteroid 1738 Oosterhoff is named after him.

References

External links Media related to Pieter Oosterhoff at Wikimedia Commons "Oosterhoff, P Th (1904–78)". Institute of Physics Publishing. 2000-11-01. Retrieved 2006-06-08.

Illustrations

Worked examples

Example 1 — a first encounter with Pieter Oosterhoff

Start with the simplest possible case. Write down what Pieter Oosterhoff 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 Pieter Oosterhoff 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 Pieter Oosterhoff 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 Pieter Oosterhoff

In research: Pieter Oosterhoff 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 Pieter Oosterhoff 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: Pieter Oosterhoff is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1904 births, 1978 deaths, 20th-century Dutch astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for Pieter Oosterhoff 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.

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How to study Pieter Oosterhoff in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Pieter Oosterhoff 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 Pieter Oosterhoff out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Pieter Oosterhoff in simple terms?

Pieter Theodorus Oosterhoff (30 March 1904, Leeuwarden - 14 March 1978, Leiden) was a Dutch astronomer. He was the co-administrator, along with Jan Oort, of the Leiden Observatory in the Netherlands.

Why does Pieter Oosterhoff 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 Pieter Oosterhoff?

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 Pieter Oosterhoff.