astronomy

HD 98219

HD 98219 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 98219 rather than just read about it. In short: HD 98219, also named Hunahpú, is a subgiant star in the constellation Crater. It has a confirmed exoplanet.

Key takeaways

HD 98219 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 98219 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 98219 from memory before moving on to harder problems.

Reference excerpt

HD 98219, also named Hunahpú, is a subgiant star in the constellation Crater. It has a confirmed exoplanet. At around 4 billion years old, it is a star around 1.3 times as massive as the Sun that has cooled and expanded to 4.5 times the Sun's diameter, brightening to be around 11 times as luminous. The International Astronomical Union (IAU) gave the opportunity to Honduras to name the star Hunahpú as part of NameExoWorlds. Hunahpú was one of the twin gods who became the Sun in K'iche' (Quiché) Mayan mythology.

Planetary system A gas giant planet with a minimum mass almost double that of Jupiter was discovered as part of a radial velocity survey of subgiant stars at Keck Observatory. The International Astronomical Union (IAU) has named it Ixbalanqué, the twin brother of Hunahpú.

References

Worked examples

Example 1 — a first encounter with HD 98219

Start with the simplest possible case. Write down what HD 98219 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 98219 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 98219 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 98219

In research: HD 98219 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 98219 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 98219 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Crater (constellation), Durchmusterung objects, Henry Draper Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 98219 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 98219 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 98219 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 98219 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 98219 in simple terms?

HD 98219, also named Hunahpú, is a subgiant star in the constellation Crater. It has a confirmed exoplanet.

Why does HD 98219 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 98219?

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 98219.