astronomy

NGC 3198

NGC 3198 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 3198 rather than just read about it. In short: NGC 3198, also known as Herschel 146 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on 15 January 1788.

Key takeaways

NGC 3198 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 3198 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of NGC 3198 from memory before moving on to harder problems.

Reference excerpt

NGC 3198, also known as Herschel 146 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on 15 January 1788. NGC 3198 is located in the Leo Spur, which is part of the Virgo Supercluster, and is approximately 47 million light years away. NGC 3198 was one of 18 galaxies targeted by the Hubble Space Telescope (HST) Key Project on the Extragalactic Distance Scale, which aimed to calibrate various secondary distance indicators and determine the Hubble constant to an accuracy of 10%. The type and orientation of NGC 3198 made it suitable for these measurements. The Wide Field and Planetary Camera 2 (WFPC2) of the HST was used to measure the magnitudes of 52 Cepheid variables, and the resulting distance modulus corresponded to a distance of 14.5 Mpc (47 million light years). Observations made with the Westerbork Synthesis Radio Telescope detected for the first time the presence of extraplanar gas. The extraplanar gas makes up approximately 15% of the total atomic hydrogen (HI) mass of the galaxy.

Supernovae Two supernovae have been observed in NGC 3198:

SN 1966J (Type Ia, mag. 13) was discovered by Paul Wild on 18 December 1966. Some sources list this supernova as a Type Ib. SN 1999bw (type gap, mag. 17.8) was discovered by the Lick Observatory Supernova Search (LOSS) on 20 April 1999. Significantly fainter than expected when discovered, it was initially classified as a Type IIn supernova. In 2021, researchers reclassified it as a gap transient.

Gallery

See also List of NGC objects (3001–4000)

References

External links Media related to NGC 3198 at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with NGC 3198

Start with the simplest possible case. Write down what NGC 3198 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 3198 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 3198 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 3198

In research: NGC 3198 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 3198 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 3198 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1788, Barred spiral galaxies, Discoveries by William Herschel, so understanding it makes those chapters shorter.
In everyday life: Look for NGC 3198 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 3198 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what NGC 3198 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 3198 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is NGC 3198 in simple terms?

NGC 3198, also known as Herschel 146 is a barred spiral galaxy in the constellation Ursa Major. It was discovered by German-British astronomer William Herschel on 15 January 1788.

Why does NGC 3198 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 3198?

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 3198.