astronomy

Messier 36

Messier 36 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 36 rather than just read about it. In short: Messier 36 or M36, also known as NGC 1960 or the Pinwheel Cluster, is an open cluster of stars in the somewhat northern Auriga constellation. It was discovered by Giovanni Batista Hodierna before 1654, who described it as a nebulous patch.

Key takeaways

Messier 36 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 36 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Messier 36 from memory before moving on to harder problems.

Reference excerpt

Messier 36 or M36, also known as NGC 1960 or the Pinwheel Cluster, is an open cluster of stars in the somewhat northern Auriga constellation. It was discovered by Giovanni Batista Hodierna before 1654, who described it as a nebulous patch. The cluster was independently re-discovered by Guillaume Le Gentil in 1749, then Charles Messier observed it in 1764 and added it to his catalogue. It is about 1,330 pc (4,340 light years) away from Earth. The cluster is very similar to the Pleiades cluster (M45), and if as far away it would be of similar apparent magnitude. This cluster has an angular diameter of 10′ and a core radius of 3.2′. It has a mass of roughly 746 M☉ and a linear tidal radius of 10.6 ± 1.6 parsecs (34.6 ± 5.2 ly). Based upon photometry, the age of the cluster has been estimated by Wu et al. (2009) as 25.1 Myr and 26.3+3.2−5.2 Myr by Bell et al. (2013). The luminosity of the stars that have not yet depleted their lithium implies an age of 22±4 Myr, in good agreement with these older estimates. M36 includes ten stars with a visual magnitude brighter than 10, and 178 down to magnitude 14. 38 members display an infrared excess, with one being particularly high. There is one candidate B-type variable star, of 9th magnitude. A 2020 study of the variable stars in the cluster estimated a new closer distance of 3,800 light years from Earth.

A young stellar object with an outflow, associated with the infrared source IRAS 05327+3404 was discovered in optical observations of M36. The object is nicknamed "Holoea", Hawaiian for "flowing gas". Despite appearing close to M36, it is probably not a part of M36, but instead it may be a member of the more distant S235 region. The young star driving the outflow was classified as transitional between class I and class II and appears to be surrounded by large amounts of circumstellar material.

Map

Illustrations

Worked examples

Example 1 — a first encounter with Messier 36

Start with the simplest possible case. Write down what Messier 36 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 36 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 36 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 36

In research: Messier 36 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 36 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 36 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astronomical objects discovered in 1654, Auriga, Messier objects, so understanding it makes those chapters shorter.
In everyday life: Look for Messier 36 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 36 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Messier 36 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 36 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Messier 36 in simple terms?

Why does Messier 36 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 36?

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 36.