astronomy

NGC 4457

NGC 4457 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 4457 rather than just read about it. In short: NGC 4457 is an intermediate spiral galaxy located about 55 million light-years away in the constellation of Virgo. It is also classified as a LINER galaxy, a class of active galaxy defined by their spectral line emissions.

Key takeaways

NGC 4457 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 4457 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 4457 from memory before moving on to harder problems.

Reference excerpt

NGC 4457 is an intermediate spiral galaxy located about 55 million light-years away in the constellation of Virgo. It is also classified as a LINER galaxy, a class of active galaxy defined by their spectral line emissions. NGC 4457 Is inclined by about 33°. It was discovered by astronomer William Herschel on February 23, 1784. Despite being listed in the Virgo Cluster Catalog as VCC 1145, NGC 4457 is a member of the Virgo II Groups which form an extension of the Virgo cluster. NGC 4457 may have had a recent minor merger with another galaxy.

Supernova On July 1 2020, an astronomical transient was discovered in NGC 4457 by astronomer Kōichi Itagaki and confirmed by ASAS-SN. Spectroscopic classification determined the object to be a Type Ia Supernova, designated SN 2020nvb.

Physical characteristics NGC 4457 has a broad oval zone containing an inner spiral which is defined mainly by two fairly open arms. There is a well-defined outer ring that is completely detached from the inner regions of the galaxy.

Truncated disk NGC 4457 has a severely reduced amount of star-formation in its disk while its inner regions have a normalized rate of massive star formation. This may have been caused by a recent interaction of the gas in the galaxy with the gas in the surrounding Virgo Cluster, causing the gas to be stripped away in an effect known as ram-pressure stripping.

See also List of NGC objects (4001–5000) Messier 90 Comet Galaxy - a distant galaxy in the cluster Abell 2667 which is experiencing ram-pressure stripping as well

References

External links

NGC 4457 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images Sasmirala page on NGC 4457

Illustrations

Worked examples

Example 1 — a first encounter with NGC 4457

Start with the simplest possible case. Write down what NGC 4457 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 4457 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 4457 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 4457

In research: NGC 4457 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 4457 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 4457 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1784, Discoveries by William Herschel, Intermediate spiral galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 4457 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 4457 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 4457 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 4457 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 4457 in simple terms?

Why does NGC 4457 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 4457?

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 4457.