astronomy

NGC 189

NGC 189 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 NGC 189 rather than just read about it. In short: NGC 189 is an open cluster in the Cassiopeia constellation. It was discovered by Caroline Herschel on 27 September 1783, and independently rediscovered by John Herschel on 27 October 1829.

Key takeaways

NGC 189 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 189 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 189 from memory before moving on to harder problems.

Reference excerpt

NGC 189 is an open cluster in the Cassiopeia constellation. It was discovered by Caroline Herschel on 27 September 1783, and independently rediscovered by John Herschel on 27 October 1829. NGC 189 orbits the Milky Way on a nearly circular orbit with an eccentricity of 0.053 and an orbital period of 231,000 years. It enters the solar circle at parts of its orbit, and is part of the thin disk of the Milky Way.

References

External links NGC 189 @ SEDS NGC objects pages NGC 189 at NightSkyInfo.com

NGC 189 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Illustrations

Worked examples

Example 1 — a first encounter with NGC 189

Start with the simplest possible case. Write down what NGC 189 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 NGC 189 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 NGC 189 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 NGC 189

In research: NGC 189 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 NGC 189 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: NGC 189 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1783, Cassiopeia (constellation), Discoveries by Caroline Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 189 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 NGC 189 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 189 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 NGC 189 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 189 in simple terms?

NGC 189 is an open cluster in the Cassiopeia constellation. It was discovered by Caroline Herschel on 27 September 1783, and independently rediscovered by John Herschel on 27 October 1829.

Why does NGC 189 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 NGC 189?

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 NGC 189.