astronomy

HD 82741

HD 82741 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 82741 rather than just read about it. In short: HD 82741 is a single star in the northern constellation of Lynx. It is visible to the naked eye with an apparent visual magnitude of 4.81.

Key takeaways

HD 82741 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 82741 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 82741 from memory before moving on to harder problems.

Reference excerpt

HD 82741 is a single star in the northern constellation of Lynx. It is visible to the naked eye with an apparent visual magnitude of 4.81. The distance to HD 82741 is 223 light years, as determined from its annual parallax shift of 14.6 mas. It is moving further from the Earth with a heliocentric radial velocity of 1 km/s. At the age of 2.74 billion years, this is an evolved giant star with a stellar classification of G9.5 IIIb Fe-1, where the suffix notation indicates an underabundance of iron in its atmosphere. It belongs to a sub-category of giants called the red clump, indicating that it is on the horizontal branch and is generating energy through the fusion of helium at its core. With 1.62 times the mass of the Sun, it has expanded to 9 times the Sun's radius. It is radiating 58.9 times the Sun's luminosity from its enlarged photosphere at an effective temperature of 4,809 K.

References

Illustrations

Worked examples

Example 1 — a first encounter with HD 82741

Start with the simplest possible case. Write down what HD 82741 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 82741 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 82741 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 82741

In research: HD 82741 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 82741 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 82741 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bright Star Catalogue objects, Durchmusterung objects, G-type giants, so understanding it makes those chapters shorter.
In everyday life: Look for HD 82741 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 82741 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 82741 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 82741 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 82741 in simple terms?

HD 82741 is a single star in the northern constellation of Lynx. It is visible to the naked eye with an apparent visual magnitude of 4.81.

Why does HD 82741 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 82741?

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 82741.