astronomy

KELT-20

KELT-20 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 KELT-20 rather than just read about it. In short: KELT-20, also known as MASCARA-2, is an A2 main sequence star in the constellation of Cygnus, about 447 light years away. A brown dwarf companion was found in 2026 with the use of radial velocity and astrometry.

Key takeaways

KELT-20 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect KELT-20 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of KELT-20 from memory before moving on to harder problems.

Reference excerpt

KELT-20, also known as MASCARA-2, is an A2 main sequence star in the constellation of Cygnus, about 447 light years away. A brown dwarf companion was found in 2026 with the use of radial velocity and astrometry.

Nomenclature KELT-20 is the star's KELT designation. It is also designated as MASCARA-2 meaning that it is the second star observed by the MASCARA exoplanet search program. Its Henry Draper Catalogue designation is HD 185603, and its Hipparcos designation is HIP 96618.

Planetary system In 2017, the discovery of the planet KELT-20b was announced.

References

Worked examples

Example 1 — a first encounter with KELT-20

Start with the simplest possible case. Write down what KELT-20 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 KELT-20 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 KELT-20 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 KELT-20

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

Read the reference excerpt below once, without taking notes.
Close the page and write down what KELT-20 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 KELT-20 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is KELT-20 in simple terms?

Why does KELT-20 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 KELT-20?

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 KELT-20.