astronomy

Messier 10

Messier 10 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 10 rather than just read about it. In short: Messier 10 or M10 (also designated NGC 6254) is a globular cluster of stars in the equatorial constellation of Ophiuchus. The object was discovered by the French astronomer Charles Messier on May 29, 1764, who cataloged it as number 10 in his catalogue and described it as a "nebula without stars".

Key takeaways

Messier 10 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 10 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Messier 10 from memory before moving on to harder problems.

Reference excerpt

Messier 10 or M10 (also designated NGC 6254) is a globular cluster of stars in the equatorial constellation of Ophiuchus. The object was discovered by the French astronomer Charles Messier on May 29, 1764, who cataloged it as number 10 in his catalogue and described it as a "nebula without stars". In 1774, German astronomer Johann Elert Bode likewise called it a "nebulous patch without stars; very pale". Using larger instrumentation, German-born astronomer William Herschel was able to resolve the cluster into its individual members. He described it as a "beautiful cluster of extremely compressed stars". William Parsons, 3rd Earl of Rosse thought he could distinguish a dark lane through part of the cluster. The first to estimate the distance to the cluster was Harlow Shapley, although his derivation of 33,000 light years was much further than the modern value. The tidal radius of M10 is 19.3 arcminutes, which is about two-thirds of the apparent diameter of the Moon. Viewed through medium-sized telescopes it appears about half that size (8–9 arcminutes), as its bright core is only 35 light-years across. It has a core radius of 48 arcseconds and a half-mass radius of 147 arcseconds (2.5 arcminutes). M10 has a spatial diameter of 83 light-years and is estimated to be 14,300 light-years away from Earth. It figures a degree west of 30 Ophiuchi, a center-of-constellation orange star. In terms of the abundance of elements other than hydrogen and helium, what astronomers term the metallicity, Messier 10 is "moderately metal–poor". The abundance of iron, measured as [Fe/H] equals –1.45 ± 0.04 dex, is only 3.5% of the abundance found at the surface of the Sun. The cluster shows evidence of being enriched by the elements generated through the s-process in massive stars and Type II supernovae. It shows little evidence of enrichment by Type Ia supernovae. Because binary stars are, on average, more massive than normal stars, the binaries tend to migrate toward the center of the cluster. The fraction of binary stars in the core region is about 14%. This proportion decreases with increasing radius to about 1.5% in the outlying regions of the cluster. Correspondingly, the core region contains a concentration of interaction-formed blue straggler stars, most of which formed 2–5 billion years ago. The density of stars in the core region is about 3.8 solar masses per cubic parsec. 35 variable stars have been discovered in this cluster, including one RR Lyrae variable, two eclipsing binaries, three W Virginis variables, five semiregular variables, and 16 SX Phoenicis variables. In addition, the cluster contains two known millisecond pulsars. The cluster is currently located about 5 kiloparsecs (16 kly) from the Galactic Center. It completes an orbit around the Milky Way galaxy about every 140 million years, during which it crosses the plane of the galactic disk every 53 million years. Its rosette orbit has an eccentricity of 0.21.

Gallery

Illustrations

Worked examples

Example 1 — a first encounter with Messier 10

Start with the simplest possible case. Write down what Messier 10 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 10 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 10 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 10

In research: Messier 10 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 10 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 10 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1764, Discoveries by Charles Messier, Globular clusters, so understanding it makes those chapters shorter.
In everyday life: Look for Messier 10 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 Messier 10 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Messier 10 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 10 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Messier 10 in simple terms?

Why does Messier 10 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 10?

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 10.