astronomy

NGC 6217

NGC 6217 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 6217 rather than just read about it. In short: NGC 6217 is a barred spiral galaxy located some 67 million light years away, in the constellation Ursa Minor. It can be located with a 10 cm (4 in) or larger telescope as an 11th magnitude object about 2.5° east-northeast of the star Zeta Ursae Minoris.

Key takeaways

NGC 6217 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 6217 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 6217 from memory before moving on to harder problems.

Reference excerpt

NGC 6217 is a barred spiral galaxy located some 67 million light years away, in the constellation Ursa Minor. It can be located with a 10 cm (4 in) or larger telescope as an 11th magnitude object about 2.5° east-northeast of the star Zeta Ursae Minoris. The galaxy is inclined by an angle of 33° to the line of sight along a position angle of 162°. A morphological classification of (R')SB(rs)bc indicates that NGC 6217 has a false outer ring-like structure formed from the spiral arms (R'), a well-defined bar running across the nucleus (SB), a partial inner ring (rs), and moderately-wound spiral arms (bc). The nucleus is spherical in shape, showing no indication of oblateness. The prominent bar spans an angular distance of 48″ (48 arc seconds) across the galaxy along a position angle of 35.97° ± 0.35°. At 10″ southeast of the nucleus is a prominent region of star formation. The inner ring is about 43″.5 across. NGC 6217 has been characterized as a starburst galaxy, which means it is undergoing a high rate of star formation compared to a typical galaxy. As a result, the spectrum is dominated by stellar photoionization from young, hot stars. This component is less than 10 million years old, producing a blue-hued spectral continuum with absorption weak lines from elements other than hydrogen and helium. At the core of the galaxy is a low-luminosity active galactic nucleus which has formed an H II region.

Supernova One supernova has been observed in NGC 6217: SN 2018gj (Type II, mag 14.6) was discovered by Patrick Wiggins on 14 January 2018.

Gallery

References

External links Media related to NGC 6217 at Wikimedia Commons "Hubble Opens New Eyes on the Universe", Hubble Site news Center, NASA, September 9, 2009, retrieved 2013-06-18 "NGC 6217". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2013-06-20.

Illustrations

Worked examples

Example 1 — a first encounter with NGC 6217

Start with the simplest possible case. Write down what NGC 6217 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 6217 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 6217 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 6217

In research: NGC 6217 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 6217 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 6217 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arp objects, Barred spiral galaxies, NGC objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 6217 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 6217 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 6217 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 6217 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 6217 in simple terms?

Why does NGC 6217 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 6217?

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 6217.