astronomy

Kepler-451

Kepler-451 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-451 rather than just read about it. In short: Kepler-451 (also known as 2MASS J19383260+4603591 and abbreviated to 2M1938+4603) is an eclipsing post-common envelope binary star system that comprises two stars, a pulsating subdwarf B star and a small red dwarf star. It is located about 1,340 light-years (410 parsecs) away in the constellation Cygnus.

Key takeaways

Kepler-451 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-451 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Kepler-451 from memory before moving on to harder problems.

Reference excerpt

Kepler-451 (also known as 2MASS J19383260+4603591 and abbreviated to 2M1938+4603) is an eclipsing post-common envelope binary star system that comprises two stars, a pulsating subdwarf B star and a small red dwarf star. It is located about 1,340 light-years (410 parsecs) away in the constellation Cygnus. It has been hypothesized to host one or more exoplanets.

Planetary system Periodic variations in the timing of this system's eclipses were detected in 2015 using data from the Kepler space telescope. It was proposed that these variations are caused by the gravitational effects of a Jupiter-mass planet, Kepler-451b, orbiting with a period of 416 days at a distance of 0.92 AU. The existence of planets in this system is disputed. An independent study in 2020 found no evidence for Kepler-451b, ruling out the presence of any object of at least Jupiter's mass on the claimed orbit with an inclination greater than 43°. A 2022 study instead proposed a three-planet model, including the originally claimed planet as well as two other planets of similar mass with orbital periods of 43 and 1,800 days. In general, eclipse timing variations of this type are common in post-common envelope binary systems, and their true cause remains uncertain. A 2026 study revised the possibility of planetary companions using 20 years of eclipse timing data. One of the models (DS-A) suggested two companions orbiting at 3.4 and 4.3 au, while the other (DS-B) suggested three companions orbiting at 0.91, 3.4 and 4.3 au. They note that the inner companion in the DS-B model could be an artifact of systematic issues, while the outer companion in both models could be explained as being the result of magnetic activity. Therefore, the data supports the presence of only one planet at 3.4 au.

References

Worked examples

Example 1 — a first encounter with Kepler-451

Start with the simplest possible case. Write down what Kepler-451 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-451 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-451 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-451

In research: Kepler-451 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-451 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-451 is common in secondary-school and first-year university syllabi. It links to neighbouring topics B-type subdwarfs, Binary stars, Cygnus (constellation), so understanding it makes those chapters shorter.
In everyday life: Look for Kepler-451 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-451 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Kepler-451 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-451 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Kepler-451 in simple terms?

Why does Kepler-451 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-451?

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-451.