astronomy

NGC 613

NGC 613 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 613 rather than just read about it. In short: NGC 613 is a barred spiral galaxy located 67 million light years away in the southern constellation of Sculptor. The galaxy was discovered by German-English astronomer William Herschel on 9 December 1798, then re-discovered and catalogued by Scottish astronomer James Dunlop on 5 August 1826.

Key takeaways

NGC 613 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 613 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 613 from memory before moving on to harder problems.

Reference excerpt

NGC 613 is a barred spiral galaxy located 67 million light years away in the southern constellation of Sculptor. The galaxy was discovered by German-English astronomer William Herschel on 9 December 1798, then re-discovered and catalogued by Scottish astronomer James Dunlop on 5 August 1826. It was first photographed in 1912, which revealed the spiral form of the nebula. During the twentieth century, radio telescope observations showed that a linear feature in the nucleus was a relatively strong source of radio emission.

NGC 613 is inclined by an angle of 37° to the line of sight from the Earth along a position angle of 125°. The morphological classification of NGC 613 is SBbc(rs), indicating that it is a spiral galaxy with a bar across the nucleus (SB), a weak inner ring structure circling the bar (rs), and moderate to loosely wound spiral arms (bc). The bar is relatively broad but irregular in profile with a position angle that varies from 115–124° and dust lanes located along the leading edges. Star formation is occurring at the ends of the bar and extending along the well-defined spiral arms. The central bulge is readily apparent, with a radius of 14″. The classification of the nucleus is of type HII, indicating a match to the spectrum of an H II region. Near the core, the stars have a velocity dispersion of 136 ± 20 km/s. The nucleus is a source of radio emission with the form of an inner ring with a radius of about 1,100 ly (350 pc) and a linear feature that is perhaps perpendicular to it. The latter consists of three discrete blobs spanning approximately 2,000 ly (600 pc). Observations suggest the presence of a supermassive black hole at the core with a mass in the range (1.9–9.6) × 107 times the mass of the Sun.

SN 2016gkg On September 20, 2016, Argentinian amateur astronomer Victor Buso captured supernova SN 2016gkg in NGC 613, just as it was starting to erupt. This was a Type IIb supernova, a supernova that initially shows a hydrogen envelope like a Type II supernova, but later loses the hydrogen lines in its spectrum to appear like a Type Ib supernova. It showed the double peak that is common to many Type IIb supernovae, rising to around magnitude 15.5 shortly after discovery and then again about 20 days later. The progenitor star has been identified in Hubble Space Telescope images from before its collapse, and it is likely to have been a yellow supergiant.

See also NGC 1079 NGC 5248 NGC 4492 NGC 1300 List of NGC objects (1–1000)

References

External links

Supernova SN 2016gkg in NGC 613 from The Virtual Telescope Project NGC 613 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 613

Start with the simplest possible case. Write down what NGC 613 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 613 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 613 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 613

In research: NGC 613 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 613 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 613 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1798, Barred spiral galaxies, Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 613 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 613 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 613 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 613 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 613 in simple terms?

Why does NGC 613 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 613?

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 613.