astronomy

Kepler-42c

Kepler-42c 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 Kepler-42c rather than just read about it. In short: Kepler-42 c, previously KOI-961.02 then KOI-961 c, is an exoplanet orbiting Kepler-42, a star located about 131 light-years (40 pc) from the Solar System, in the constellation of Cygnus. A planetary system of at least three exoplanets with sizes between Mars and Venus has been detected around this red dwarf on January 11, 2012, by the method of transits with the help of the space telescope Kepler.

Key takeaways

Kepler-42c belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Kepler-42c to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kepler-42c from memory before moving on to harder problems.

Reference excerpt

Kepler-42 c, previously KOI-961.02 then KOI-961 c, is an exoplanet orbiting Kepler-42, a star located about 131 light-years (40 pc) from the Solar System, in the constellation of Cygnus. A planetary system of at least three exoplanets with sizes between Mars and Venus has been detected around this red dwarf on January 11, 2012, by the method of transits with the help of the space telescope Kepler. Kepler-42 c is a planet with a radius 0.73 times that of Earth. It orbits its star in a little less than 11 hours at about 0.006 AU of its host star and has an average equilibrium temperature of about 445 °C (833 °F). Due to the temperature, it is not suitable for life. It is tidally locked in a synchronous rotation. Thus, it makes one complete rotation each time it completes an orbit. As a result, there is an eternal day side and a permanent night side.

References

Illustrations

Worked examples

Example 1 — a first encounter with Kepler-42c

Start with the simplest possible case. Write down what Kepler-42c 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 Kepler-42c 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 Kepler-42c 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 Kepler-42c

In research: Kepler-42c 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 Kepler-42c 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: Kepler-42c is common in secondary-school and first-year university syllabi. It links to neighbouring topics Cygnus (constellation), Exoplanet stubs, Exoplanets discovered by the Kepler space telescope, so understanding it makes those chapters shorter.
In everyday life: Look for Kepler-42c 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 Kepler-42c in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kepler-42c 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 Kepler-42c out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kepler-42c in simple terms?

Why does Kepler-42c 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 Kepler-42c?

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 Kepler-42c.