astronomy

NGC 2174

NGC 2174 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 2174 rather than just read about it. In short: NGC 2174 (also known as Monkey Head Nebula) is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175. It was discovered on 6 February 1877 by French astronomer Édouard Stephan.

Key takeaways

NGC 2174 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 2174 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 2174 from memory before moving on to harder problems.

Reference excerpt

NGC 2174 (also known as Monkey Head Nebula) is an H II emission nebula located in the constellation Orion and is associated with the open star cluster NGC 2175. It was discovered on 6 February 1877 by French astronomer Édouard Stephan. It is thought to be located about 6,400 light-years away from Earth. The nebula may have formed through hierarchical collapse. There is some equivocation in the use of the identifiers NGC 2174 and NGC 2175. These may apply to the entire nebula, to its brightest knot, or to the star cluster it includes. Burnham's Celestial Handbook lists the entire nebula as 2174/2175 and does not mention the star cluster. The NGC Project (working from the original descriptive notes) assigns NGC 2174 to the prominent knot at J2000 06h 09m 23.7s, +20° 39′ 34″ and NGC 2175 to the entire nebula, and by extension to the star cluster. SIMBAD uses NGC 2174 for the nebula and NGC 2175 for the star cluster.

Glowing gas and dark dust do not survive well in the Monkey Head Nebula. Young stars near the center of the nebula generate stellar winds and high energy radiation that causes the nebula's material to shift into complex shapes. The nebula is primarily composed of hydrogen which glows at infrared wavelengths due to the radiation.

Hubble 24th Anniversary Images (2014)

Gallery

See also List of NGC objects (2001–3000)

References

External links

NASA Astronomy Picture of the Day: NGC 2174: Emission Nebula in Orion (8 December 2006) NASA Astronomy Picture of the Day: NGC 2174: Stars Versus Mountains (9 February 2011) NASA Astronomy Picture of the Day: At the Edge of NGC 2174 (3 April 2014) Monkey Head Nebula at Constellation Guide

Illustrations

Worked examples

Example 1 — a first encounter with NGC 2174

Start with the simplest possible case. Write down what NGC 2174 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 2174 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 2174 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 2174

In research: NGC 2174 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 2174 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 2174 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1877, Discoveries by Édouard Stephan, H II regions, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 2174 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 2174 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 2174 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 2174 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 2174 in simple terms?

Why does NGC 2174 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 2174?

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 2174.