astronomy

NGC 4561

NGC 4561 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 4561 rather than just read about it. In short: NGC 4561 is a barred spiral galaxy in the constellation Coma Berenices. It was discovered by German-British astronomer William Herschel on April 13, 1784.

Key takeaways

NGC 4561 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 4561 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 4561 from memory before moving on to harder problems.

Reference excerpt

NGC 4561 is a barred spiral galaxy in the constellation Coma Berenices. It was discovered by German-British astronomer William Herschel on April 13, 1784. This galaxy is located at a distance of 82 ± 14 million light-years (25.2 ± 4.3 Mpc) from the Milky Way, and is a member of the Virgo Cluster of galaxies. It is 13th magnitude with an angular size of 1.5′. The morphological classification of NGC 4561 in the De Vaucouleurs system is SB(rs)dm, indicating a barred spiral galaxy (SB) with a transitional inner ring structure (rs), loosely wound spiral arms (d), and an irregular appearance with no bulge component (m). The galactic plane is inclined at an angle of 28° to the plane of the sky, with the major axis aligned along a position angle of 60°. It has a star formation rate of 0.23 M☉·yr−1. The net stellar mass of the galaxy is 1.23×109 M☉. A nuclear X-ray source was detected in NGC 4561 by Chandra, and was determined to be an active galactic nucleus based on XMM-Newton observations. It has a small supermassive black hole at the source, with a mass of at least 2×104 M☉.

References

External links Media related to NGC 4561 at Wikimedia Commons NGC 4561 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 4561

Start with the simplest possible case. Write down what NGC 4561 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 4561 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 4561 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 4561

In research: NGC 4561 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 4561 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 4561 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Barred spiral galaxies, Coma Berenices, Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 4561 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 4561 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 4561 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 4561 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 4561 in simple terms?

NGC 4561 is a barred spiral galaxy in the constellation Coma Berenices. It was discovered by German-British astronomer William Herschel on April 13, 1784.

Why does NGC 4561 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 4561?

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 4561.