astronomy

WASP-166

WASP-166 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 WASP-166 rather than just read about it. In short: WASP-166, also named Filetdor, is an F-type main-sequence star 373 light-years (114 parsecs) away in the constellation Hydra. With an apparent magnitude of 9.4, it is too faint to be visible to the naked eye.

Key takeaways

WASP-166 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect WASP-166 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of WASP-166 from memory before moving on to harder problems.

Reference excerpt

WASP-166, also named Filetdor, is an F-type main-sequence star 373 light-years (114 parsecs) away in the constellation Hydra. With an apparent magnitude of 9.4, it is too faint to be visible to the naked eye. It hosts one known exoplanet.

Nomenclature The designation WASP-166 comes from the Wide Angle Search for Planets. This was one of the 20 systems selected to be named in the third NameExoWorlds campaign, beginning in August 2022. The approved names, proposed by a team from Spain, were announced in June 2023. The star is named Filetdor and its planet is named Catalineta, after characters from a Mallorcan folktale about a golden sea serpent, Na Filet d'Or.

Planetary system

The planet WASP-166b, later named Catalineta, is a hot, low-density super-Neptune, discovered in 2018 using the transit method as part of the Wide Angle Search for Planets. It is a rare example of a planet within the Neptune desert; few Neptune-mass planets are found so close to their stars. The orbit of WASP-166b is aligned with its host star's equator, differing from other similar hot Neptunes (such as HAT-P-11b, WASP-107b and GJ 436 b) which have misaligned orbits. The aligned orbit suggests that it is unlikely to have undergone high-eccentricity migration. While initial transmission spectroscopy observations of WASP-166b with the HARPS spectrograph failed to detect any molecules in the planet's atmosphere, follow-up studies of the same dataset and of ESPRESSO data have detected sodium in the atmosphere. ESPRESSO has also been used to place constraints on the possible presence of water vapor and clouds.

Worked examples

Example 1 — a first encounter with WASP-166

Start with the simplest possible case. Write down what WASP-166 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 WASP-166 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 WASP-166 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 WASP-166

In research: WASP-166 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 WASP-166 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: WASP-166 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Durchmusterung objects, F-type main-sequence stars, Hydra (constellation), so understanding it makes those chapters shorter.
In everyday life: Look for WASP-166 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 WASP-166 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what WASP-166 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 WASP-166 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is WASP-166 in simple terms?

Why does WASP-166 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 WASP-166?

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 WASP-166.