astronomy

HD 105382

HD 105382 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 HD 105382 rather than just read about it. In short: HD 105382 (also known as V863 Centauri) is a star in the constellation Centaurus. Its apparent magnitude is 4.47, making it visible to the naked eye under good observing conditions.

Key takeaways

HD 105382 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HD 105382 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 105382 from memory before moving on to harder problems.

Reference excerpt

HD 105382 (also known as V863 Centauri) is a star in the constellation Centaurus. Its apparent magnitude is 4.47, making it visible to the naked eye under good observing conditions. From parallax measurements, it is located 130 parsecs (440 light years) from the Sun.

In 1992, Luis A. Balona et al. announced their discovery that HD 105382 is a variable star. It was given its variable star designation, V863 Centauri, in 1993. HD 105382's apparent magnitude varies with an amplitude of 0.012 over a period of 1.295 days. It has been previously classified as a Be star, which would explain the variability as stellar pulsations, but this classification was probably due to accidental observation of the nearby Be star δ Centauri. A 2004 study showed that the 1.295 day period is actually the rotation period of the star, and that the variability is caused by non-homogeneous distribution of elements in the stellar surface. In particular, HD 105382 is a helium-weak chemically peculiar star with a helium abundance varying between 0.5% and 15% of the solar abundance, and a silicon abundance varying between 0.00044% and 0.0069% the solar value. Regions with more helium appear to coincide with the regions with less silicon, and vice versa. This peculiar abundance pattern is probably related to HD 105382's magnetic field, which has a polar strength of 2.3 kG. From astrometric measurements by the Hipparcos spacecraft, HD 105382 is identified as a probable astrometric binary. It is only 267" away from δ Centauri, and both stars appear to be at the same distance from Earth and have the same motion through space, so they may be related. In total, this may be a five star system. It is a member of the Lower Centaurus–Crux (LCC) subgroup of the Scorpius–Centaurus association.

References

Illustrations

Worked examples

Example 1 — a first encounter with HD 105382

Start with the simplest possible case. Write down what HD 105382 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 HD 105382 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 HD 105382 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 HD 105382

In research: HD 105382 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 HD 105382 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: HD 105382 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Astrometric binaries, B-type giants, Bright Star Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 105382 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 HD 105382 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 105382 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 HD 105382 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 105382 in simple terms?

HD 105382 (also known as V863 Centauri) is a star in the constellation Centaurus. Its apparent magnitude is 4.47, making it visible to the naked eye under good observing conditions.

Why does HD 105382 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 HD 105382?

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 HD 105382.