astronomy

NGC 1808

NGC 1808 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 1808 rather than just read about it. In short: NGC 1808 is a barred spiral galaxy located in the southern constellation of Columba, about two degrees to the south and east of Gamma Caeli. It was discovered on 10 May 1826 by Scottish astronomer James Dunlop, who described it as a "faint nebula".

Key takeaways

NGC 1808 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 1808 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 1808 from memory before moving on to harder problems.

Reference excerpt

NGC 1808 is a barred spiral galaxy located in the southern constellation of Columba, about two degrees to the south and east of Gamma Caeli. It was discovered on 10 May 1826 by Scottish astronomer James Dunlop, who described it as a "faint nebula". The galaxy is a member of the NGC 1808 group, which is part of the larger Dorado Group. The morphological classification of this galaxy is (R)SAB(s)a, which indicates a spiral galaxy with a weak-bar around the nucleus (SAB), no ring around the bar (s), an outer ring (R), and tightly-wound spiral arms (a). It is inclined by an angle of 57° to the line of sight from the Earth, with the long axis oriented at a position angle of 324°. The disk of gas and stars shows a noticeable warp, and there is a pronounced asymmetry in the distribution of neutral hydrogen and H II regions.

The core region contains a suspected weak active galactic nucleus plus a circumnuclear ring containing star clusters and supernova remnants at a distance of ~280 pc from the center. These form a ring of peculiar "hot spots". It was formerly identified as a possible Seyfert galaxy, but evidence now points to starburst activity in a ~500 pc radius around the center. A probable outflow of gas is directed to the north-east from the nucleus, forming prominent dust lanes. The high level of star formation in this galaxy and the nearby NGC 1792 may indicate a recent, distant tidal interaction between the two.

Supernova One supernova has been observed in NGC 1808: SN 1993af (Type Ia, mag. 17) was discovered by Marina Wischnjewsky on 15 November 1993 at 220″ east and 94″ north of the galactic nucleus.

Image Gallery

See also List of NGC objects (1001–2000)

References

External links Media related to NGC 1808 at Wikimedia Commons Pictures and description at Hubble Heritage website

Illustrations

Worked examples

Example 1 — a first encounter with NGC 1808

Start with the simplest possible case. Write down what NGC 1808 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 1808 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 1808 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 1808

In research: NGC 1808 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 1808 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 1808 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1826, Columba (constellation), Discoveries by James Dunlop, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 1808 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 1808 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 1808 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 1808 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 1808 in simple terms?

Why does NGC 1808 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 1808?

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 1808.