astronomy

Qatar-3

Qatar-3 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 Qatar-3 rather than just read about it. In short: Qatar-3 is a 12th magnitude star located in the northern constellation Andromeda. It is host to a transiting planet.

Key takeaways

Qatar-3 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Qatar-3 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Qatar-3 from memory before moving on to harder problems.

Reference excerpt

Qatar-3 is a 12th magnitude star located in the northern constellation Andromeda. It is host to a transiting planet. With a radial velocity of 10.99 km/s, it is drifting away from the Solar System, and is currently located 2,400 light years away based on its annual parallax.

Properties This star is a G-type star with 14.5% more mass than the Sun, and 27.2% larger. It has a luminosity of almost two times that of the Sun, and has effective temperature of 5,991 K, which gives it a yellow hue. Qatar-3 is also a metal poor star that has a similar metallicity to the Sun, and has a rapid rotation rate of 10.4 km/s. This means it takes Qatar-3 6.31 days to complete a full rotation, while the Sun takes almost a month to rotate.

Planetary system In 2016, the Qatar Exoplanet Survey discovered a planet around Qatar-3, Qatar-4, and Qatar-5, which was led by an international team in Qatar. Qatar-3b is a massive planet, with 4.31 times the mass of Jupiter, and has a similar radius to the latter. With a density of 4.0 g/cm3, this is one of the densest planets discovered. With an effective temperature of 1,681 K, it is a scorching planet.

Qatar-3b Qatar-3b is a hot Jupiter. It orbits its star every 2.5 days. It was discovered in 2016 by the Qatar Exoplanet Survey (QES). This planet was discovered by QES along with Qatar-4b and Qatar-5b. The light curves of the planet's respective host stars have been observed as well during the survey, along with their stellar properties.

Orbit This planet is another typical hot Jupiter. It orbits very close to its star with a period of 2 days, 12 hours, 11 minutes, and 24 seconds. This corresponds with an orbital distance of about 0.04 AU, which is 10 times closer to its star than Mercury is to the Sun. With an eccentricity of 0, this suggests that Qatar-3b is on a perfectly circular orbit.

Physical properties Qatar-3b is a massive planet, with 4.31 times the mass of Jupiter, but a similar radius. With a density of 4.0 g cm−3, this is one of the densest planets discovered. With an effective temperature of 1,681 K, it is a scorched planet.

References

Worked examples

Example 1 — a first encounter with Qatar-3

Start with the simplest possible case. Write down what Qatar-3 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 Qatar-3 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 Qatar-3 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 Qatar-3

In research: Qatar-3 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 Qatar-3 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: Qatar-3 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Andromeda (constellation), G-type subgiants, Planetary systems with one confirmed planet, so understanding it makes those chapters shorter.
In everyday life: Look for Qatar-3 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 Qatar-3 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Qatar-3 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 Qatar-3 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Qatar-3 in simple terms?

Qatar-3 is a 12th magnitude star located in the northern constellation Andromeda. It is host to a transiting planet.

Why does Qatar-3 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 Qatar-3?

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 Qatar-3.