astronomy

NGC 339

NGC 339 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 339 rather than just read about it. In short: NGC 339 is a globular cluster in the constellation Tucana the Toucan. It is located both visually and physically in the Small Magellanic Cloud, being only about 10,000 ± 12,000 light years (3,000 ± 3,000 parsecs) closer than the cloud.

Key takeaways

NGC 339 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 339 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 339 from memory before moving on to harder problems.

Reference excerpt

NGC 339 is a globular cluster in the constellation Tucana the Toucan. It is located both visually and physically in the Small Magellanic Cloud, being only about 10,000 ± 12,000 light years (3,000 ± 3,000 parsecs) closer than the cloud. It is rather prominent, being the brightest cluster in the southern reaches of the cloud. It was discovered by John Herschel on September 18, 1835. It was observed in 2005 by the Hubble Space Telescope. Its apparent V-band magnitude is 12.12, but at this wavelength, it has 0.19 magnitudes of interstellar extinction. NGC 339 is about 6.3 billion years old. Its estimated mass is 5.7×104 M☉, and its total luminosity is 7.2×104 L☉, leading to a mass-to-luminosity ratio of 0.79 M☉/L☉. All else equal, older star clusters have higher mass-to-luminosity ratios; that is, they have lower luminosities for the same mass.

References

External links Media related to NGC 339 at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with NGC 339

Start with the simplest possible case. Write down what NGC 339 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 339 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 339 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 339

In research: NGC 339 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 339 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 339 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1835, Discoveries by John Herschel, Globular clusters, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 339 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 NGC 339 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 339 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 339 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 339 in simple terms?

Why does NGC 339 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 339?

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 339.