astronomy

NGC 4869

NGC 4869 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 4869 rather than just read about it. In short: NGC 4869 is an elliptical galaxy located in the constellation of Coma Berenices. It is located 343 million light years from Earth.

Key takeaways

NGC 4869 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 4869 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 4869 from memory before moving on to harder problems.

Reference excerpt

NGC 4869 is an elliptical galaxy located in the constellation of Coma Berenices. It is located 343 million light years from Earth. The galaxy was discovered by William Herschel in April 1785 but also observed by both John Herschel and Heinrich d'Arrest, in March 1827 and May 1863 respectively. It is a member of the Coma Cluster with a small companion galaxy at a position angle of 325°.

Characteristics NGC 4869 is classified as a radio galaxy with a faint radio core with two oppositely directed radio jets and a lengthy low-surface brightness tail. It has an estimated γ-ray luminosity of Lγ ≤ 4 × 1039 erg s−1 like NGC 4874. There is also an elongated absorption feature in the galaxy, possibly representing an edge on disk. NGC 4869 contains a narrow angle tailed radio source. The source is found lying towards the central region of the Coma Cluster by 111 kpc. It shows a mean fractional polarization of 18% at 4.535 GHz and 21% at 8.465 GHz and a large-scale structure that is almost 200 kpc. A characteristic feature of the source, is a sharp bend towards a north direction at 3’5 from the host galaxy's position. According to a Chandra X-ray image of NGC 4869, a straight collimated jet is seen flaring when traversing a surface brightness edge.

Supermassive black hole The supermassive black hole in NGC 4869 is estimated to be 1.32 × 108 M☉ (108.12 M☉) based on a study made by Jong-Hak Woo and Urry in 2002.

References

External links

NGC 4869 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images NGC 4869 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with NGC 4869

Start with the simplest possible case. Write down what NGC 4869 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 4869 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 4869 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 4869

In research: NGC 4869 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 4869 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 4869 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1785, Coma Berenices, Coma Cluster, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 4869 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 4869 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 4869 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 4869 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 4869 in simple terms?

NGC 4869 is an elliptical galaxy located in the constellation of Coma Berenices. It is located 343 million light years from Earth.

Why does NGC 4869 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 4869?

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 4869.