science

NGC 2173

NGC 2173 is a science 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 2173 rather than just read about it. In short: NGC 2173 is a globular cluster of stars in the southern constellation of Mensa. It was discovered on February 8, 1836 by English astronomer John Herschel.

Key takeaways

NGC 2173 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect NGC 2173 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 2173 from memory before moving on to harder problems.

Reference excerpt

NGC 2173 is a globular cluster of stars in the southern constellation of Mensa. It was discovered on February 8, 1836 by English astronomer John Herschel. The cluster has an apparent visual magnitude of 11.88, and an angular size of 2.60″. It is located at a distance of approximately 159,000 ly (48.7 kpc) from the Sun. The cluster is located within the Large Magellanic Cloud, to the southeast of the galaxy's center at a separation of around 11,000 ly (3.5 kpc). A 1986 age estimate based on the main sequence turnoff found a value of 1.8±0.7 Gyr. This was later refined to 1.7±0.2 Gyr. Variations in lower mass element abundances suggest that the cluster has at least two distinct stellar populations with different ages. In 2018, it was announced by Li et al (2018) that the blue straggler stars in the cluster formed two distinct sequences. However, an objection was raised that this finding was an artifact of field contamination: by applying decontamination techniques, one of the sequences could be shown to be unrelated to the cluster. With the availability of higher precision proper motion data, the existence of the bifurcatated sequence was apparently reconfirmed by Wang et al (2025).

References

Illustrations

Worked examples

Example 1 — a first encounter with NGC 2173

Start with the simplest possible case. Write down what NGC 2173 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 2173 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 2173 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 2173

In research: NGC 2173 appears in science 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 2173 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 2173 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Discoveries by John Herschel, Globular clusters, Large Magellanic Cloud, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 2173 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 2173 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 2173 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 2173 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 2173 in simple terms?

NGC 2173 is a globular cluster of stars in the southern constellation of Mensa. It was discovered on February 8, 1836 by English astronomer John Herschel.

Why does NGC 2173 matter?

Because it connects several science 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 2173?

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 2173.