astronomy

HAT-P-26

HAT-P-26 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-26 rather than just read about it. In short: HAT-P-26 is a K-type main-sequence star located about 466 light-years (143 parsecs) away in the constellation of Virgo. A survey in 2015 did not find any stellar companions in orbit around it, although a red dwarf companion with a temperature 4000+100−350 K is suspected on wide orbit.

Key takeaways

HAT-P-26 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-26 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HAT-P-26 from memory before moving on to harder problems.

Reference excerpt

HAT-P-26 is a K-type main-sequence star located about 466 light-years (143 parsecs) away in the constellation of Virgo. A survey in 2015 did not find any stellar companions in orbit around it, although a red dwarf companion with a temperature 4000+100−350 K is suspected on wide orbit.

Nomenclature The designation HAT-P-26 indicates that this was the 26th star found to have a planet by the HATNet Project. In August 2022, this planetary system was included among 20 systems to be named by the third NameExoWorlds project. The approved names, proposed by a team from Puerto Rico, were announced in June 2023. HAT-P-26 is named Guahayona and its planet is named Guataubá, after figures from Taíno mythology.

Planetary system In 2010 a transiting hot Neptune planet was detected. The transiting planet HAT-P-26b was detected by the HATNet Project using telescopes located in Hawaii and Arizona. The planet is likely formed by pebble accretion mechanism. The transmission spectrum of HAT-P-26b was taken in 2015, with the best fit favouring either a cloudless atmosphere or an atmosphere with a low-lying cloud deck. The atmospheric composition of the planet was measured in 2019, and a water vapor volume fraction of 1.5+2.1−0.9% was detected. HAT-P-26 is carbon depleted, with a C/O ratio constrained to less than 0.33. Also, the planet's atmosphere contains light metal hydrides. The measured planetary temperature is equal to 563+58−54 K. In 2023, the atmosphere of the planet was found to contain 2.4%+2.9%−1.6% water vapor at a temperature of 590+60−50 K. A 2019 study detected transit-timing variations (TTVs) of HAT-P-26b, the cause of which was unclear at that time. With more data by 2023, it was suggested that the TTVs may be caused by a second planet in the system. In 2024, a candidate second planet, about twice the size of Earth and slightly farther from the star than planet b, was detected by transit in TESS data, but requires further observations to be fully confirmed.

Notes

References

Worked examples

Example 1 — a first encounter with HAT-P-26

Start with the simplest possible case. Write down what HAT-P-26 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-26 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-26 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-26

In research: HAT-P-26 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-26 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-26 is common in secondary-school and first-year university syllabi. It links to neighbouring topics K-type main-sequence stars, Planetary systems with one confirmed planet, Planetary transit variables, so understanding it makes those chapters shorter.
In everyday life: Look for HAT-P-26 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-26 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HAT-P-26 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-26 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HAT-P-26 in simple terms?

Why does HAT-P-26 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-26?

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-26.