astronomy

HAT-P-13

HAT-P-13 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 HAT-P-13 rather than just read about it. In short: HAT-P-13, also known as GSC 03416-00543, is a G-type subgiant approximately 800 light-years away in the constellation Ursa Major. In 2009 it was discovered that this star is orbited by two massive planets, the innermost of which transits the star.

Key takeaways

HAT-P-13 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HAT-P-13 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HAT-P-13 from memory before moving on to harder problems.

Reference excerpt

HAT-P-13, also known as GSC 03416-00543, is a G-type subgiant approximately 800 light-years away in the constellation Ursa Major. In 2009 it was discovered that this star is orbited by two massive planets, the innermost of which transits the star. This was the first known example of an extrasolar transiting planet with an additional planet in the same system. In 2015, a spectroscopic study have revealed a very strong starspot activity of the HAT-P-13 star.

Planetary system As of 2009, HAT-P-13 has been confirmed to have two extrasolar planets orbiting it. The inner planet was discovered by the transit method and the outer planet was found through the radial velocity method. A search for transits by HAT-P-13c was negative, however only 72% of the possible transit configurations could be ruled out. HAT-P-13 was the first star to have a transiting planet and an additional planet on a known orbit. HAT-P-7 and other planets are known to have additional companions, but there is not enough data to characterize the system. OGLE-TR-111 has one confirmed transiting planet, and one unconfirmed transiting planet. The innermost planet, HAT-P-13b, has a mass around 90% that of Jupiter and orbits its sun every 2.91624039 days. This classifies the planet as a hot Jupiter, with temperatures exceeding 1000 kelvins. The second companion, HAT-P-13c, has a mass over 15 Jupiters. Because of its mass, this companion could either be a massive planet or a low mass brown dwarf. Either way, HAT-P-13 c orbits its sun every 446 days in an eccentric orbit. Radial velocity measurements also suggest the existence of a third more distant companion in the system. This may be an additional planet, or it may be a brown dwarf or even a small star.

See also HAT-P-12 HATNet Project OGLE-TR-111

References

Worked examples

Example 1 — a first encounter with HAT-P-13

Start with the simplest possible case. Write down what HAT-P-13 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 HAT-P-13 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 HAT-P-13 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 HAT-P-13

In research: HAT-P-13 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 HAT-P-13 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: HAT-P-13 is common in secondary-school and first-year university syllabi. It links to neighbouring topics G-type subgiants, Planetary systems with two confirmed planets, Planetary transit variables, so understanding it makes those chapters shorter.
In everyday life: Look for HAT-P-13 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 HAT-P-13 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HAT-P-13 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 HAT-P-13 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HAT-P-13 in simple terms?

Why does HAT-P-13 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 HAT-P-13?

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 HAT-P-13.