astronomy

Lacaille 8760

Lacaille 8760 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 Lacaille 8760 rather than just read about it. In short: Lacaille 8760 (AX Microscopii) is a red dwarf star in the constellation Microscopium. It is one of the nearest stars to the Sun at about 12.9 light-years' distance, and the brightest M-class main-sequence star in Earth's night sky, although it is generally too faint to be seen without a telescope.

Key takeaways

Lacaille 8760 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Lacaille 8760 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Lacaille 8760 from memory before moving on to harder problems.

Reference excerpt

Lacaille 8760 (AX Microscopii) is a red dwarf star in the constellation Microscopium. It is one of the nearest stars to the Sun at about 12.9 light-years' distance, and the brightest M-class main-sequence star in Earth's night sky, although it is generally too faint to be seen without a telescope. At an apparent magnitude of +6.7, it may only be visible to the unaided eye under exceptionally good viewing conditions, under dark skies. This star was originally listed in a 1763 catalog that was published posthumously by the French Abbé Nicolas-Louis de Lacaille. He observed it in the southern sky while working from an observatory at the Cape of Good Hope. Number 8760 was assigned to this star in the 1847 edition of Lacaille's catalogue of 9,766 stars by Francis Baily. In the past, Lacaille 8760 has been classified anywhere from spectral class K7 down to M2. In 1979, the Irish astronomer Patrick Byrne discovered that it is a flare star, and it was given the variable star designation AX Microscopii, or AX Mic. As a flare star it is relatively quiescent.

Lacaille 8760 is one of the largest and brightest red dwarfs known, with about 60% the mass and 51% the radius of the Sun. It is about five billion years old and is spinning at a projected rotational velocity of 3.3 km/s. The star is radiating 7.2% of the luminosity of the Sun from its photosphere at an effective temperature of 3,800 K. Despite efforts by astronomers, as of 2011 no planets had been detected in orbit around this star. Lacaille 8760 orbits around the galaxy with a relatively high ellipticity of 0.23. Its closest approach to the Sun occurred about 20,000 years ago when it came within 12 light-years (3.7 parsecs). Due to its low mass (60% of the Sun), it has an expected lifespan of about 75 billion (7.5 × 1010) years, seven times longer than the Sun's.

References

External links SolStation article

Illustrations

Worked examples

Example 1 — a first encounter with Lacaille 8760

Start with the simplest possible case. Write down what Lacaille 8760 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 Lacaille 8760 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 Lacaille 8760 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 Lacaille 8760

In research: Lacaille 8760 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 Lacaille 8760 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: Lacaille 8760 is common in secondary-school and first-year university syllabi. It links to neighbouring topics BY Draconis variables, Durchmusterung objects, Flare stars, so understanding it makes those chapters shorter.
In everyday life: Look for Lacaille 8760 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 Lacaille 8760 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Lacaille 8760 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 Lacaille 8760 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Lacaille 8760 in simple terms?

Why does Lacaille 8760 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 Lacaille 8760?

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 Lacaille 8760.