astronomy

NGC 5221

NGC 5221 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 5221 rather than just read about it. In short: NGC 5221 is a spiral galaxy in the constellation of Virgo. Its velocity with respect to the cosmic microwave background is 7,258±21 km/s, which corresponds to a Hubble distance of 349.2 ± 24.5 Mly (107.06 ± 7.50 Mpc).

Key takeaways

NGC 5221 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 5221 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 5221 from memory before moving on to harder problems.

Reference excerpt

NGC 5221 is a spiral galaxy in the constellation of Virgo. Its velocity with respect to the cosmic microwave background is 7,258±21 km/s, which corresponds to a Hubble distance of 349.2 ± 24.5 Mly (107.06 ± 7.50 Mpc). However, eight non-redshift measurements give a closer mean distance of 317.31 ± 5.34 Mly (97.288 ± 1.638 Mpc). It was discovered by German-British astronomer William Herschel on 12 April 1784. NGC 5221 is a radio galaxy, i.e. it has giant regions of radio emission extending well beyond its visible structure.

Arp 288

NGC 5221 together with NGC 5222 and PGC 93122 are catalogued as Arp 288 by Halton Arp in his Atlas of Peculiar Galaxies, in the category of "wind effects." The group is described by Arp as "Streamers in both directions from edge of spiral." The three galaxies are also listed as VV 315 in the Vorontsov-Vel'yaminov Interacting Galaxies catalogue.

Supernova One supernova has been observed in NGC 5221:

SN 2016bln (Type Ia-91T, mag. 19.2) was discovered by the Palomar Transient Factory on 4 April 2016. At the time, it was described as "one of the earliest detections of an over-luminous SN Ia made to date."

Image gallery

See also List of NGC objects (5001–6000) Atlas of Peculiar Galaxies

References

External links Media related to NGC 5221 at Wikimedia Commons NGC 5221 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images

Illustrations

Worked examples

Example 1 — a first encounter with NGC 5221

Start with the simplest possible case. Write down what NGC 5221 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 5221 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 5221 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 5221

In research: NGC 5221 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 5221 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 5221 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1784, Discoveries by William Herschel, IRAS catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 5221 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study NGC 5221 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 5221 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 5221 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 5221 in simple terms?

Why does NGC 5221 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 5221?

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 5221.