astronomy

NGC 3859

NGC 3859 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 3859 rather than just read about it. In short: NGC 3859 is a spiral galaxy located about 295 million light-years away in the constellation Leo. It was discovered by astronomer Édouard Stephan on March 23, 1884.

Key takeaways

NGC 3859 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 3859 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 3859 from memory before moving on to harder problems.

Reference excerpt

NGC 3859 is a spiral galaxy located about 295 million light-years away in the constellation Leo. It was discovered by astronomer Édouard Stephan on March 23, 1884. The galaxy is a member of the Leo Cluster.

Physical characteristics Deep imaging of NGC 3859 by Yagi et al. have revealed a distorted faint halo which is elongated toward the northeast along the major axis of the galaxy. On the southwestern side of the galaxy, the halo extends about ~33,000 ly (10 kpc) above the disk of the galaxy. To the north, there is a small dwarf galaxy which is possibly an interacting companion. A part of the extended halo of NGC 3859 may be the result of an interaction between the dwarf and NGC 3859.

Hα emission The bright disk Hα emission in the disk together with the very blue color of the galaxy and the emission line dominated nuclear spectrum indicate that NGC 3859 is a starburst galaxy. The morphology of the Hα emission of NGC 3859 is peculiar, characterized by two narrow spurs which extend to the northwest and the southeast from the galaxy disk. Their widths are ~6,500 ly (2 kpc) and ~33,000 ly (10 kpc) respectively. The morphology and size of the two spurs of NGC 3859 are quite similar to the Hα nebula and extended ionized gas cloud which suggest that the spurs originated in a starburst superbubble or superwind. The northern part of an Hα nebula of NGC 3859 seems to be flowing toward the northeast. Also, the two spurs of the galaxy are bending in the same direction. These morphological characteristics suggest that the hot gas of the galaxy is being affected by ram pressure from the southwest. However, there is no indication of one-sided elongation of ionized gas within the galaxy. There is also no sharp cutoff at the southwest edge of the Hα nebula, and no extended part of the Hα emission out of the galaxy to the northeast, but it shows an extension toward the east-southeast. In addition, the northern faint flowing part of the nebular continuum is overlapped by the dwarf companion galaxy suggesting that this part of the Hα nebula could have been formed by a galaxy interaction rather than ram pressure. Therefore, ram pressure stripping may not be strong enough to create the overall structure of the extended ionized gas cloud (EIG) around NGC 3859.

SN 2014U On February 23, 2014, a Type II supernova designated as SN 2014U was discovered in NGC 3859.

See also List of NGC objects (3001–4000) NGC 3079-galaxy with starburst superbubble Messier 82-nearby galaxy undergoing a starburst

References

External links

NGC 3859 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 3859

Start with the simplest possible case. Write down what NGC 3859 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 3859 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 3859 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 3859

In research: NGC 3859 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 3859 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 3859 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1884, Discoveries by Édouard Stephan, Interacting galaxies, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 3859 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 3859 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 3859 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 3859 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 3859 in simple terms?

NGC 3859 is a spiral galaxy located about 295 million light-years away in the constellation Leo. It was discovered by astronomer Édouard Stephan on March 23, 1884.

Why does NGC 3859 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 3859?

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 3859.