astronomy

NGC 6221

NGC 6221 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 6221 rather than just read about it. In short: NGC 6221 (also known as PGC 59175) is a barred spiral galaxy located in the constellation Ara. In de Vaucouleurs' galaxy morphological classification scheme, it is classified as SB(s)bc and was discovered by British astronomer John Herschel on 3 May 1835.

Key takeaways

NGC 6221 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 6221 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 6221 from memory before moving on to harder problems.

Reference excerpt

NGC 6221 (also known as PGC 59175) is a barred spiral galaxy located in the constellation Ara. In de Vaucouleurs' galaxy morphological classification scheme, it is classified as SB(s)bc and was discovered by British astronomer John Herschel on 3 May 1835. NGC 6221 is located at about 69 million light years from Earth.

Galaxy group information NGC 6221 is part of galaxy group NGC 6221/15, which includes spiral galaxy NGC 6215 and three dwarf galaxies. Interactions between NGC 6221 and NGC 6215 form a double-stranded bridge of neutral hydrogen gas over a projected distance of 100 kpc; Dwarf 3 of the three dwarf galaxies may have formed from the bridging gas.

Supernovae Two supernovae have been observed in NGC 6221:

SN 1990W (Type Ib/Ic, mag. 15) was discovered by Robert Evans on 16 August 1990. SN 2024pxg (Type II, mag. 15.1) was discovered by the Distance Less Than 40 Mpc Survey (DLT40) on 23 July 2024.

See also List of NGC objects (6001–7000) New General Catalogue

References

External links Media related to NGC 6221 at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with NGC 6221

Start with the simplest possible case. Write down what NGC 6221 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 6221 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 6221 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 6221

In research: NGC 6221 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 6221 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 6221 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Ara (constellation), Barred spiral galaxies, Barred spiral galaxy stubs, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 6221 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 6221 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 6221 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 6221 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 6221 in simple terms?

Why does NGC 6221 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 6221?

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 6221.