astronomy

HD 118889

HD 118889 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 118889 rather than just read about it. In short: HD 118889 is a binary star system in the northern constellation of Boötes. It is faintly visible to the naked eye as a point of light with an apparent visual magnitude of 5.57.

Key takeaways

HD 118889 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 118889 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 118889 from memory before moving on to harder problems.

Reference excerpt

HD 118889 is a binary star system in the northern constellation of Boötes. It is faintly visible to the naked eye as a point of light with an apparent visual magnitude of 5.57. The system is located at a distance of approximately 196 light years from the Sun based on stellar parallax, but is drifting closer with a radial velocity of −26 km/s. The binary components of this system were first measured by S. W. Burnham in 1878 and it was given the discovery code BU 612. The pair are orbiting each other with a period of 22.46 years with an eccentricity (ovalness) of 0.545. The primary component is magnitude 6.35, with the secondary slightly fainter at magnitude 6.47. A third star, 3.5″ away, is a 12th-magnitude common-proper-motion companion. Any orbit would take over a thousand years.

References

External links HR 5138 CCDM J13395+1045 Image HD 118889

Worked examples

Example 1 — a first encounter with HD 118889

Start with the simplest possible case. Write down what HD 118889 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 118889 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 118889 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 118889

In research: HD 118889 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 118889 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 118889 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Binary stars, Boötes, Bright Star Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 118889 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 118889 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 118889 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 118889 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 118889 in simple terms?

HD 118889 is a binary star system in the northern constellation of Boötes. It is faintly visible to the naked eye as a point of light with an apparent visual magnitude of 5.57.

Why does HD 118889 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 118889?

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 118889.