astronomy

NGC 1241

NGC 1241 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 1241 rather than just read about it. In short: NGC 1241 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of about 150 million light years from Earth, which, given its apparent dimensions, means that NGC 1241 is about 140,000 light years across.

Key takeaways

NGC 1241 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 1241 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 1241 from memory before moving on to harder problems.

Reference excerpt

NGC 1241 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of about 150 million light years from Earth, which, given its apparent dimensions, means that NGC 1241 is about 140,000 light years across. It was discovered by William Herschel on January 10, 1785. It is classified as a Seyfert galaxy. NGC 1241 interacts with its smaller companion NGC 1242, forming a pair collectively known in the Atlas of Peculiar Galaxies as Arp 304.

Characteristics NGC 1241 is a barred spiral galaxy seen at an inclination. It has two well defined dusty spiral arms, and thus is characterised as a grand design spiral galaxy. The bulge is boxy, characteristic of a barred galaxy, with the arms emerging from each end of the bar, with the north one appearing more tightly wound than the southern. The main arms branch into smaller ones. A circumnuclear ring with active star formation has been detected in the central region of the galaxy. It appears clumpy and inclined and measures 5.6 × 3.4 arcseconds in diameter, lying just inside the inner Lindblad resonance. A faint spiral pattern with leading arms has been found to emanate from it in Paα emission, while in Ks and J band, the pattern appears trailing. NGC 1241 is one of the few galaxies with known trailing features in the nuclear regions, with the other being NGC 6902. Inside the circumnuclear ring was detected a bar like feature 1.6 arcseconds long that is almost perpendicular to the main bar of the galaxy. The nucleus of NGC 1241 has been found to be active and it has been categorised as a type II Seyfert galaxy. The most accepted theory for the energy source of active galactic nuclei is the presence of an accretion disk around a supermassive black hole. The mass of the black hole in the centre of NGC 1241 is estimated to be 107.46 (29 million) M☉. The star formation rate of NGC 1241 is estimated to be 3.07 M☉ per year based on the H-alpha flux.

Nearby galaxies NGC 1241 forms a pair with NGC 1242, which lies at an angular separation of 1.6 arcminutes. NGC 1243 lies 3.1 arcminutes away, but it has been identified as a double star in our galaxy. According to Garcia et al. the pair of galaxies is part of a galaxy group known as LGG 84, which also includes the galaxies NGC 1247, MCG -02-09-006, and Markarian 1071. A more recent study placed NGC 1241 in the same group as the galaxies NGC 1185, NGC 1204, NGC 1214, NGC 1215, NGC 1238, and NGC 1247.

Gallery

See also NGC 7469, another interacting Seyfert galaxy with a circumnuclear star formation ring

References

External links

NGC 1241 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images NGC 1241 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with NGC 1241

Start with the simplest possible case. Write down what NGC 1241 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 1241 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 1241 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 1241

In research: NGC 1241 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 1241 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 1241 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1785, Barred spiral galaxies, Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 1241 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 1241 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 1241 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 1241 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 1241 in simple terms?

Why does NGC 1241 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 1241?

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 1241.