astronomy

KOI-74

KOI-74 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 KOI-74 rather than just read about it. In short: KOI-74 (KIC 6889235) is an eclipsing binary star in the constellation of Cygnus. The primary star is an A-type main-sequence star with a temperature of 9,400 K (9,130 °C; 16,460 °F).

Key takeaways

KOI-74 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect KOI-74 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of KOI-74 from memory before moving on to harder problems.

Reference excerpt

KOI-74 (KIC 6889235) is an eclipsing binary star in the constellation of Cygnus. The primary star is an A-type main-sequence star with a temperature of 9,400 K (9,130 °C; 16,460 °F). It lies in the field of view of the Kepler Mission and was determined to have a companion object in orbit around it which is smaller and hotter than the main star.

KOI-74b KOI-74b is a hot compact object orbiting KOI-74. It was discovered in 2010 by the Kepler Mission and came to attention because of its small size (its radius is only 4.3% of the solar radius) and high temperature of 13,000 K (12,700 °C; 22,900 °F). The orbit of KOI-74b around the main star takes 5.18875 days to complete. Analysis of relativistic boosting of light in the Kepler data indicates that it is likely to be a low mass white dwarf of approximately 0.22 solar masses, resulting from an earlier phase of mass transfer in a binary system when the object underwent its giant phase.

See also KOI-81, a similar system also discovered by the Kepler Mission. Kepler Object of Interest, stars observed to have transits by the Kepler Mission

References

Illustrations

Worked examples

Example 1 — a first encounter with KOI-74

Start with the simplest possible case. Write down what KOI-74 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 KOI-74 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 KOI-74 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 KOI-74

In research: KOI-74 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 KOI-74 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: KOI-74 is common in secondary-school and first-year university syllabi. It links to neighbouring topics A-type main-sequence stars, Cygnus (constellation), Eclipsing binaries, so understanding it makes those chapters shorter.
In everyday life: Look for KOI-74 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 KOI-74 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what KOI-74 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 KOI-74 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is KOI-74 in simple terms?

KOI-74 (KIC 6889235) is an eclipsing binary star in the constellation of Cygnus. The primary star is an A-type main-sequence star with a temperature of 9,400 K (9,130 °C; 16,460 °F).

Why does KOI-74 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 KOI-74?

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 KOI-74.