astronomy

NGC 739

NGC 739 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 739 rather than just read about it. In short: NGC 739 is a spiral galaxy approximately 193 million light-years away from Earth in the constellation of Triangulum. Observational history NGC 739 was discovered by English astronomer Ralph Copeland on January 9, 1874.

Key takeaways

NGC 739 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 739 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 739 from memory before moving on to harder problems.

Reference excerpt

NGC 739 is a spiral galaxy approximately 193 million light-years away from Earth in the constellation of Triangulum.

Observational history NGC 739 was discovered by English astronomer Ralph Copeland on January 9, 1874. He was using the 72" telescope at Birr Castle in an observation of Arp 166, which is composed of two interacting galaxies NGC 750 and NGC 751. Copeland reported the wrong direction of the newly observed galaxy, but gave the correct orientation as PA 292° (WNW) and separation 524" (8.7'). Because of his error the derived position was in error and this was copied into the NGC Catalogue. In 1913 American astronomer Heber Curtis noted there was nothing at that position and suggested MCG +05-05-030 was in fact NGC 739, based on Edward Crossley's photographs taken at Lick Observatory.

See also Spiral galaxy List of NGC objects (1–1000) Triangulum (constellation)

References

External links

NGC 739 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 739

Start with the simplest possible case. Write down what NGC 739 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 739 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 739 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 739

In research: NGC 739 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 739 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 739 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1874, Discoveries by Ralph Copeland, NGC objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 739 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 739 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 739 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 739 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 739 in simple terms?

NGC 739 is a spiral galaxy approximately 193 million light-years away from Earth in the constellation of Triangulum. Observational history NGC 739 was discovered by English astronomer Ralph Copeland on January 9, 1874.

Why does NGC 739 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 739?

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 739.