astronomy

Messier 98

Messier 98 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 Messier 98 rather than just read about it. In short: Messier 98, M98 or NGC 4192 is an intermediate spiral galaxy about 44.4 million light-years away in slightly northerly Coma Berenices, about 6° to the east of the bright star Denebola (Beta Leonis). It was discovered by French astronomer Pierre Méchain on 1781, along with nearby M99 and M100, and was catalogued by compatriot Charles Messier 29 days later in his Catalogue des Nébuleuses & des amas d'Étoiles.

Key takeaways

Messier 98 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Messier 98 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Messier 98 from memory before moving on to harder problems.

Reference excerpt

Messier 98, M98 or NGC 4192 is an intermediate spiral galaxy about 44.4 million light-years away in slightly northerly Coma Berenices, about 6° to the east of the bright star Denebola (Beta Leonis). It was discovered by French astronomer Pierre Méchain on 1781, along with nearby M99 and M100, and was catalogued by compatriot Charles Messier 29 days later in his Catalogue des Nébuleuses & des amas d'Étoiles. It has a blueshift, denoting ignoring of its fast other movement (vectors of proper motion), it is approaching at about 140 km/s. The morphological classification of this galaxy is SAB(s)ab, which indicates it is a spiral galaxy that displays mixed barred and non-barred features with intermediate to tightly wound arms and no ring. It is highly inclined to the line of sight at an angle of 74° and has a maximum rotation velocity of 236 km/s. The combined mass of the stars in this galaxy is an estimated 76 billion (7.6 × 1010) times the mass of the Sun. It contains about 4.3 billion solar masses of neutral hydrogen and 85 million solar masses in dust. The nucleus is active, displaying characteristics of a "transition" type object. That is, it shows properties of a LINER-type galaxy intermixed with an H II region around the nucleus. Messier 98 is a member of the Virgo Cluster, which is a large cluster of galaxies, part of the local supercluster. About 750 million years ago, it may have interacted with the large spiral galaxy Messier 99. These are now separated by 1,300,000 ly (400,000 pc).

See also List of Messier objects Messier 86, another blueshifted galaxy

References

External links

Spiral Galaxy M98 @ SEDS Messier pages Messier 98 on WikiSky: DSS2, SDSS, GALEX, IRAS, Hydrogen α, X-Ray, Astrophoto, Sky Map, Articles and images Messier Object 98

Illustrations

Worked examples

Example 1 — a first encounter with Messier 98

Start with the simplest possible case. Write down what Messier 98 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 Messier 98 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 Messier 98 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 Messier 98

In research: Messier 98 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 Messier 98 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: Messier 98 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1781, Coma Berenices, Discoveries by Pierre Méchain, so understanding it makes those chapters shorter.
In everyday life: Look for Messier 98 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Messier 98 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Messier 98 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 Messier 98 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Messier 98 in simple terms?

Why does Messier 98 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 Messier 98?

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 Messier 98.