astronomy

NGC 772

NGC 772 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 772 rather than just read about it. In short: NGC 772 is a large unbarred spiral galaxy approximately 106 million light-years away in the constellation Aries. Alternatively, it is known as Arp 78 or the Fiddlehead Galaxy.

Key takeaways

NGC 772 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 772 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 772 from memory before moving on to harder problems.

Reference excerpt

NGC 772 is a large unbarred spiral galaxy approximately 106 million light-years away in the constellation Aries. Alternatively, it is known as Arp 78 or the Fiddlehead Galaxy. It was discovered by German-British astronomer William Herschel on 29 November 1785.

Characteristics At around 200,000 light years in diameter, NGC 772 is somewhat larger than the Milky Way Galaxy, and is surrounded by several satellite galaxies – including the dwarf elliptical, NGC 770 – whose tidal forces on the larger galaxy have likely caused the emergence of a single elongated outer spiral arm that is much more developed and stronger than the other arms. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78, where it is described as a "Spiral galaxy with a small high-surface brightness companion". NGC 772 probably has a H II nucleus, but it may be a transitional object.

Supernovae

Three supernovae have been observed in NGC 772:

SN 2003hl (Type II, mag. 16.5) was discovered by LOTOSS (Lick Observatory and Tenagra Observatory Supernova Searches) on 20 August 2003. SN 2003iq (Type II, mag. 16.4) was discovered by Jean-Marie Llapasset on 8 October 2003. This supernova was visible at the same time as SN 2003hl, which had been discovered 7 weeks prior. SN 2022qze (Type II-P, mag. 19.89) was discovered by Pan-STARRS on 8 August 2022.

Gallery

Illustrations

Worked examples

Example 1 — a first encounter with NGC 772

Start with the simplest possible case. Write down what NGC 772 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 772 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 772 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 772

In research: NGC 772 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 772 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 772 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Aries (constellation), Arp objects, Astronomical objects discovered in 1785, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 772 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 772 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 772 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 772 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 772 in simple terms?

NGC 772 is a large unbarred spiral galaxy approximately 106 million light-years away in the constellation Aries. Alternatively, it is known as Arp 78 or the Fiddlehead Galaxy.

Why does NGC 772 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 772?

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 772.