astronomy

NGC 3516

NGC 3516 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 3516 rather than just read about it. In short: NGC 3516 is a barred lenticular galaxy in the constellation of Ursa Major. NGC 3516 is located about 150 million light years away from Earth, which means, given its apparent dimensions, that NGC 3516 is approximately 100,000 light years across.

Key takeaways

NGC 3516 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 3516 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 3516 from memory before moving on to harder problems.

Reference excerpt

NGC 3516 is a barred lenticular galaxy in the constellation of Ursa Major. NGC 3516 is located about 150 million light years away from Earth, which means, given its apparent dimensions, that NGC 3516 is approximately 100,000 light years across. It was discovered by William Herschel on April 3, 1785.

Characteristics In 1943, this galaxy was one of six nebulae listed by American astronomer Carl Keenan Seyfert that showed broad emission lines in their nuclei. Members of this class of objects became known as Seyfert galaxies, and they were noted to have a higher than normal surface brightness in their nuclei. NGC 3516 is believed to host a supermassive black hole whose mass is estimated to be (4.27±1.46)×107 M☉ based on broad emission-line reverberation mapping or 23000000 M☉ as measured based on velocity dispersion. Due to its high brightness in both UV and X-rays, and its prominent and clear active galactic nucleus absorption features, it has been an ideal laboratory for studying the AGN warm-absorber outflows with high-resolution spectroscopy. Over the past few decades, there have been many UV and X-ray case studies of the ionized outflows in NGC 3516. NGC 3516 has been a remarkably variable AGN, showing changes in both the intrinsic continuum and the intrinsic absorption by the ionized outflows. In 2014, the broad lines almost disappeared, probably becoming obstructed, and thus the galaxy has been identified as a changing-look AGN, meaning it changed spectra between type 1 and type 2 AGN. The galaxy has been found to emit radiowaves, with the source extending towards the north for about 0.65 arcseconds. That structure is a bit curved and probably is related to the gaseous outflow. A spiral dust feature measuring 3 arcseconds in diameter is visible north of the nucleus. A blue filamentary feature is visible northeast of the nucleus and another blue feature is visible 1.5 arcseconds southwest of the nucleus.

Nearby galaxies NGC 3516 is a relatively isolated galaxy. Near galaxies include NGC 3147 with its group that NGC 3155, UGC 5570, UGC 5686, and UGC 5689, NGC 3183, NGC 3348, and NGC 3364. Garcia identified NGC 3516 as a member of group that also includes the galaxies NGC 3348, and NGC 3364.

References

External links NGC 3516 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images NGC 3516 on SIMBAD

Illustrations

Worked examples

Example 1 — a first encounter with NGC 3516

Start with the simplest possible case. Write down what NGC 3516 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 3516 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 3516 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 3516

In research: NGC 3516 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 3516 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 3516 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1785, Barred lenticular galaxies, Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 3516 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 3516 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 3516 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 3516 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 3516 in simple terms?

Why does NGC 3516 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 3516?

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 3516.