astronomy

HD 90853

HD 90853 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 90853 rather than just read about it. In short: HD 90853 is a single star in the southern constellation Carina. It has the Bayer designation s Carinae, while HD 90853 is the identifier from the Henry Draper catalogue.

Key takeaways

HD 90853 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 90853 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 90853 from memory before moving on to harder problems.

Reference excerpt

HD 90853 is a single star in the southern constellation Carina. It has the Bayer designation s Carinae, while HD 90853 is the identifier from the Henry Draper catalogue. This is a suspected variable star with an apparent visual magnitude reported to vary between 3.79 and 3.83, and thus is bright enough to be visible to the naked eye. It is located at a distance of approximately 1,340 light-years from the Sun based on parallax, and has an absolute magnitude of −4.44. The star is drifting further away with a radial velocity of +9 km/s. This is an aging bright giant or supergiant star that has been assigned stellar classifications of F2II and F0Ib, respectively. It has seven times the mass of the Sun and has expanded to 45 times the Sun's radius. It is spinning with a projected rotational velocity of 22 km/s. The star is radiating 3,466 times the luminosity of the Sun from its enlarged photosphere at an effective temperature of 6,598 K.

References

Illustrations

Worked examples

Example 1 — a first encounter with HD 90853

Start with the simplest possible case. Write down what HD 90853 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 90853 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 90853 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 90853

In research: HD 90853 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 90853 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 90853 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bayer objects, Bright Star Catalogue objects, Carina (constellation), so understanding it makes those chapters shorter.
In everyday life: Look for HD 90853 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.

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study HD 90853 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 90853 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 90853 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 90853 in simple terms?

HD 90853 is a single star in the southern constellation Carina. It has the Bayer designation s Carinae, while HD 90853 is the identifier from the Henry Draper catalogue.

Why does HD 90853 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 90853?

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 90853.