astronomy

NGC 2293

NGC 2293 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 2293 rather than just read about it. In short: NGC 2293 is a lenticular galaxy located in the constellation Canis Major. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2293 is about 160,000 light years across.

Key takeaways

NGC 2293 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 2293 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 2293 from memory before moving on to harder problems.

Reference excerpt

NGC 2293 is a lenticular galaxy located in the constellation Canis Major. It is located at a distance of circa 100 million light years from Earth, which, given its apparent dimensions, means that NGC 2293 is about 160,000 light years across. It was discovered by John Herschel on January 20, 1835. NGC 2293 forms a pair with NGC 2292 and has an HI ring that surrounds both galaxies. The orange color and the bright center of the galaxies gives them a resemblance to carved pumpkins on Halloween.

Characteristics NGC 2293 is a lenticular galaxy with hints of a spiral structure. The old stars that make it give the galaxy an orange color. Located 0.8 arcminutes away from NGC 2292 lies NGC 2293. Both galaxies appear to share a common envelope and a complete ring of neutral hydrogen gas (HI) has been found to encircle both galaxies. The ring apparently has a color change to the southwestern view, that has been attributed to the presence of star formation. On the other hand, there is a marked absence of HI near the centre of the two galaxies. The total HI mass is 0.75×109 M☉. It is possible that the ring is the result of an ongoing merger between the two galaxies, that would result in a giant elliptical galaxy. Various models have been suggested for the formation of the ring. The most likely model is the collision between one of the two galaxies and one more galaxy that swept gas away, with the star formation region on the ring been created by a density wave or it is a population that was stripped by the intruder galaxy. It has not been ruled out that the positioning is a projection effect of two galaxies separated by a few million light years. Based on far infrared observations there is an extensive amount of cold dust at the pair, with temperature 13 K, which is lower than dust temperatures found in spiral and interacting galaxies. The temperature indicates however that it is not of primordial origin.

Nearby galaxies NGC 2292/2293 pair belongs to a galaxy group known as LGG 138. Other members of the group are the spiral galaxy NGC 2280, NGC 2295, ESO 490−G010 and ESO 490−G045. Because of its large angular diameter, about one degree, the group was identified when redshift information were available, by Garcia et al. in 1993.

References

External links NGC 2293 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 2293

Start with the simplest possible case. Write down what NGC 2293 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 2293 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 2293 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 2293

In research: NGC 2293 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 2293 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 2293 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1835, Canis Major, Discoveries by John Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 2293 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 2293 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 2293 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 2293 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 2293 in simple terms?

Why does NGC 2293 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 2293?

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 2293.