astronomy

NGC 4490

NGC 4490 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 4490 rather than just read about it. In short: NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. It was discovered by German-British astronomer William Herschel on 14 January 1788.

Key takeaways

NGC 4490 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 4490 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 4490 from memory before moving on to harder problems.

Reference excerpt

NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. It was discovered by German-British astronomer William Herschel on 14 January 1788. It is known to be one of the closest interacting/merging galactic systems. The galaxy lies at a distance of 25 million light years from Earth. It interacts with its smaller companion NGC 4485 and as a result is a starburst galaxy. NGC 4490 and NGC 4485 are collectively known in the Atlas of Peculiar Galaxies as Arp 269. The two galaxies have already made their closest approach and are rushing away from each other. It has been discovered that NGC 4490 has a double nucleus. NGC 4490 is located 45 arcminutes northwest of beta Canum Venaticorum and with apparent visual magnitude 9.8, can be observed with 15x100 binoculars. It is a member of the Herschel 400 Catalogue. It belongs to the Canes II Group. NGC 4490 has a system of satellite galaxies oriented roughly in a plane.

Stellar stream A stellar stream 25,000 light years long connects the two interacting galaxies. The stellar stream is made of bright knots and large gas rich pockets. Young blue hot massive stars are formed in this region.

Supernovae and Luminous Red Nova Two supernovae and one luminous red nova (LRN) have been observed in NGC 4490:

SN 1982F (type unknown, mag. 16) was discovered by Swiss astronomer Paul Wild on 15 April 1982. SN 2008ax (Type II, mag. 13) was discovered by the Lick Observatory Supernova Search (LOSS) on 3 March 2008 and by Kōichi Itagaki on 4 March 2008. AT 2011kp (type LRN, mag. 16.7) was discovered by Giancarlo Cortini and Stefano Antonellini on 16 August 2011.

Gallery

See also Barred spiral galaxy Canes Venatici (constellation)

References

External links

NGC 4490 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images SEDS

Illustrations

Worked examples

Example 1 — a first encounter with NGC 4490

Start with the simplest possible case. Write down what NGC 4490 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 4490 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 4490 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 4490

In research: NGC 4490 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 4490 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 4490 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arp objects, Astronomical objects discovered in 1788, Barred spiral galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 4490 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 4490 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 4490 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 4490 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 4490 in simple terms?

NGC 4490, also known as the Cocoon Galaxy, is a barred spiral galaxy in the constellation Canes Venatici. It was discovered by German-British astronomer William Herschel on 14 January 1788.

Why does NGC 4490 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 4490?

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 4490.