science

Lambda Orionis Cluster

Lambda Orionis Cluster is a science 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 Lambda Orionis Cluster rather than just read about it. In short: The Lambda Orionis Cluster (also known as the Collinder 69) is an open star cluster located north-west of the star Betelgeuse in the constellation of Orion. It is about five million years old and roughly 1,300 ly (400 pc) away from the Sun.

Key takeaways

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

Reference excerpt

The Lambda Orionis Cluster (also known as the Collinder 69) is an open star cluster located north-west of the star Betelgeuse in the constellation of Orion. It is about five million years old and roughly 1,300 ly (400 pc) away from the Sun. Included within the cluster is the double star Meissa (Lambda Orionis). With the rest of Orion, it is visible from the middle of August in the morning sky, to late April before Orion becomes too close to the Sun to be seen well. It can be seen from both the Northern Hemisphere and the Southern Hemisphere.

Description The cluster is following an orbit through the Milky Way that has a period of 227.4 million years with an ellipticity of 0.06, carrying it as far as 28 kly (8.6 kpc) from the Galactic Center, and as close as 25 kly (7.7 kpc). The inclination of the orbit carries it up to 260 light-years (80 parsecs) away from the galactic plane. On average it crosses the plane every 33.3 million years. The star cluster is young and contains a large number of low-mass stars, some T Tauri stars and brown dwarfs. One notable member is LOri167, which is a wide binary consisting of a potential planetary-mass object and a brown dwarf. Observations of the star cluster with the Spitzer Space Telescope have shown that 25% of the low-mass stars and 40% of the substellar objects are surrounded by a circumstellar disk. Two of these being actively photoevaporated by Meissa.

Molecular ring and cluster evolution

The cluster might have formed in the central region of an elongated cloud, which is supported by the distribution of pre-main-sequence star candidates, which are concentrated in the cluster and nearby regions in an elongated shape. Massive OB stars and low-mass stars formed in the central regions of these clouds. The low-mass stars closest to the massive stars likely lost their circumstellar disks due to photoevaporation. Many low-mass stars parsecs away were unaffected by this and represent the current population of low-mass stars with a circumstellar disk. The cluster is surrounded by a large molecular ring, called the Lambda Orionis ring. This was interpreted as a remnant of a supernova that exploded one million years ago. The supernova blast encountered the clouds and gas in the region and the blast dispersed the parent core, creating the molecular ring.

See also Other celestial bodies included in the constellation Orion:

Orion Nebula Horsehead Nebula Barnard 30

References

Sky Atlas 2000.0 Second Edition

External links Media related to Collinder 69 at Wikimedia Commons

Illustrations

Worked examples

Example 1 — a first encounter with Lambda Orionis Cluster

Start with the simplest possible case. Write down what Lambda Orionis Cluster claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 Lambda Orionis Cluster 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 Lambda Orionis Cluster 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 Lambda Orionis Cluster

In research: Lambda Orionis Cluster appears in science 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 Lambda Orionis Cluster 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: Lambda Orionis Cluster is common in secondary-school and first-year university syllabi. It links to neighbouring topics Open clusters, Orion (constellation), so understanding it makes those chapters shorter.
In everyday life: Look for Lambda Orionis Cluster 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 Lambda Orionis Cluster in 20 minutes

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

Frequently asked questions

What is Lambda Orionis Cluster in simple terms?

Why does Lambda Orionis Cluster matter?

Because it connects several science 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 Lambda Orionis Cluster?

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 Lambda Orionis Cluster.