astronomy

NGC 390

NGC 390 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 390 rather than just read about it. In short: NGC 390 is a star located in the constellation Pisces. It was discovered on November 19, 1884 by Guillaume Bigourdan.

Key takeaways

NGC 390 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 390 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 390 from memory before moving on to harder problems.

Reference excerpt

NGC 390 is a star located in the constellation Pisces. It was discovered on November 19, 1884 by Guillaume Bigourdan. It was described by Dreyer as very faint, very small, stellar." However, this position precesses to a position where there is nothing apart from a few scattered stars. Bigourdan's original measurements point exactly to a star, which is the most likely candidate for NGC 390; however, as a result of this confusion, a galaxy nearby (PGC 4021) has sometimes been mistaken as NGC 390.

References

Illustrations

Worked examples

Example 1 — a first encounter with NGC 390

Start with the simplest possible case. Write down what NGC 390 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 390 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 390 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 390

In research: NGC 390 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 390 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 390 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1884, Discoveries by Guillaume Bigourdan, NGC objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 390 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 390 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 390 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 390 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 390 in simple terms?

NGC 390 is a star located in the constellation Pisces. It was discovered on November 19, 1884 by Guillaume Bigourdan.

Why does NGC 390 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 390?

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 390.