astronomy

NGC 5195

NGC 5195 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 5195 rather than just read about it. In short: NGC 5195 (also known as Messier 51b or M51b) is a dwarf galaxy that is interacting with the Whirlpool Galaxy (also known as M51a or NGC 5194). Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici.

Key takeaways

NGC 5195 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 5195 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 5195 from memory before moving on to harder problems.

Reference excerpt

NGC 5195 (also known as Messier 51b or M51b) is a dwarf galaxy that is interacting with the Whirlpool Galaxy (also known as M51a or NGC 5194). Both galaxies are located approximately 25 million light-years away in the constellation Canes Venatici. Together, the two galaxies are one of the most famous interacting galaxy pairs.

History NGC 5195 was discovered by Pierre Méchain on March 20, 1781.

Interaction with the Whirlpool Galaxy NGC 5195 and the Whirlpool Galaxy compose one of the most noted interacting galaxy pairs in astronomy. The two galaxies are listed in the Atlas of Peculiar Galaxies as one of several prominent examples of a spiral galaxy with a companion galaxy. The system was also the subject of very early theoretical investigations into galaxy interactions. The two galaxies are connected by a dust-rich tidal bridge. The dust in this tidal bridge can be seen silhouetted against the center of NGC 5195. This demonstrates that NGC 5195 appears to lie behind the Whirlpool Galaxy. The encounter has significantly enhanced the spiral structure of M51.

A three-pronged structure extends from NGC 5195. The middle prong seems to be bluer than the other prongs, suggesting that this feature is an extension of the Whirlpool Galaxy’s tidal tails. The structure leads to several massive plumes and streams of stars produced by the interaction with the aforementioned grand-design spiral galaxy. One massive plume is called the "Northwest Plume". However, diffuse high-speed gas within the plume suggests an origin within the Whirlpool Galaxy and not NGC 5195. The Northwest plume partially overlaps and blends it with two stellar streams extending from NGC 5195. Unlike the northwest plume, the stellar streams are bifurcated and similar in color to NGC 5195. A 2015 study observing the Whirlpool galaxy and its companion found two new and very faint tidal structures. One of them is called the "South Plume" while the other one is called the "Northeast Plume". In January 2016, BBC science reporter Jonathan Webb said, "Astronomers have spotted two huge waves of gas being 'burped' by the black hole at the heart of a nearby galaxy. The swathes of hot gas, detected in X-ray images from NASA's Chandra space telescope, appear to be sweeping cooler hydrogen gas ahead of them. This vast, rippling belch is taking place in NGC 5195 – a small, neglected sibling of the 'Whirlpool Galaxy', 26 million light years away. That makes it one of the closest black holes blasting gas in this way". He added, "The findings, presented at the 227th meeting of the American Astronomical Society (AAS) in Florida, are a dramatic example of 'feedback' between a supermassive black hole and its host galaxy". Webb's report cited Marie Machacek, co-author of the study from the Harvard–Smithsonian Center for Astrophysics (CFA), as saying, "We think that feedback keeps galaxies from becoming too large ... But at the same time, it can be responsible for how some stars form. This shows that black holes can create, not just destroy."

Morphology As a consequence of the gravitational interaction with the Whirlpool Galaxy, NGC 5195 is highly distorted. Classification of its morphology is difficult, as it is sometimes identified as a lenticular galaxy or as an amorphous or irregular galaxy. It has been described as falling outside the standard morphological classification system.

Supernova SN 1945A is the only supernova that has been detected within NGC 5195. It was found 10″ northwest of the nucleus on April 6, 1945, by Milton L. Humason using the 100-inch (2.5 m) telescope at Mount Wilson Observatory. The supernova, classified as a Type I supernova, reached a peak apparent magnitude of 14.0.

See also NGC 1097 NGC 1167 Dwingeloo 1 List of NGC objects (5001–6000)

References

External links

SEDS: Irregular Galaxy M51B (NGC 5195) "NGC 5195 at ESA/Hubble". Archived from the original on July 8, 2009. Retrieved November 8, 2011.

Illustrations

Worked examples

Example 1 — a first encounter with NGC 5195

Start with the simplest possible case. Write down what NGC 5195 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 5195 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 5195 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 5195

In research: NGC 5195 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 5195 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 5195 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Arp objects, Astronomical objects discovered in 1781, Canes Venatici, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 5195 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 5195 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 5195 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 5195 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 5195 in simple terms?

Why does NGC 5195 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 5195?

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 5195.