astronomy

NGC 517

NGC 517 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 517 rather than just read about it. In short: NGC 517, also occasionally referred to as PGC 5214 or UGC 960, is a lenticular galaxy located approximately 188 million light-years from the Solar System in the constellation Pisces. It was discovered on 13 September 1784 by astronomer William Herschel.

Key takeaways

NGC 517 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 517 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 517 from memory before moving on to harder problems.

Reference excerpt

NGC 517, also occasionally referred to as PGC 5214 or UGC 960, is a lenticular galaxy located approximately 188 million light-years from the Solar System in the constellation Pisces. It was discovered on 13 September 1784 by astronomer William Herschel.

Observation history

Herschel discovered the object along with NGC 515 using Beta Andromedae as a reference star. He described his discovery as "two, both stellar", indicating his misidentification of the object as a star. While Herschel only noted one position about 35" east of NGC 515, Heinrich d'Arrest made the first accurate measurement of the object, using observation data of three separate nights. The object was also observed by John Herschel, son of William Herschel and later catalogued by John Louis Emil Dreyer in the New General Catalogue, where the galaxy was described as "pretty faint, round, stellar, southeastern of 2" with the other one being NGC 515.

Description The galaxy has an apparent visual magnitude of 12.5 and can be classified as type S0 using the Hubble Sequence. The object's distance of roughly 190 million light-years from the Solar System can be estimated using its redshift and Hubble's law.

See also Lenticular galaxy List of NGC objects (1–1000) Pisces (constellation)

References

External links

NGC 517 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images SEDS

Illustrations

Worked examples

Example 1 — a first encounter with NGC 517

Start with the simplest possible case. Write down what NGC 517 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 517 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 517 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 517

In research: NGC 517 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 517 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 517 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1784, Discoveries by William Herschel, Lenticular galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 517 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 517 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 517 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 517 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 517 in simple terms?

Why does NGC 517 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 517?

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 517.