astronomy

LTT 9779 b

LTT 9779 b 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 LTT 9779 b rather than just read about it. In short: LTT 9779 b, officially named Cuancoá, is a Neptune-sized planet orbiting the sunlike star LTT 9779, or Uúba. As of 2023, it has the highest-known albedo of any planet.

Key takeaways

LTT 9779 b belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect LTT 9779 b to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of LTT 9779 b from memory before moving on to harder problems.

Reference excerpt

LTT 9779 b, officially named Cuancoá, is a Neptune-sized planet orbiting the sunlike star LTT 9779, or Uúba. As of 2023, it has the highest-known albedo of any planet. It was discovered in 2020 using data from the Transiting Exoplanet Survey Satellite (TESS), and is also called TOI-193 b.

Characteristics LTT 9779 b is one of the few known planets in the Neptunian desert. It is highly reflective, with an albedo of 0.73±0.11 (reflects 73% of light +/- 11%) . This makes it the most reflective exoplanet discovered so far. It completes an orbit around LTT 9779 in less than a day, making temperatures on the day side soar to over 2,000 degrees Celsius. Global climate models of the planet indicate it has a very metal-rich atmosphere, with clouds made of silicate likely being present. Being in the Neptunian desert, LTT 9779 b is a very rare class of planet, with few like it being known. It is estimated that only 1 in 200 Sun-like stars possess a planet with an orbital period of less than a day, and most of those are Hot Jupiters or rocky planets, with ultra-hot Neptune planets being rare. Because of this, LTT 9779 b has been extensively studied by many space telescopes including Hubble and James Webb (JWST). A study using JWST NIRISS found highly reflective white clouds on the western dayside of LTT 9779b. The researchers suggest an eastwards equatorial jet, leading to a colder western dayside, allowing the formation of silicate clouds. These clouds can be best described as composed of MgSiO3 (enstatite) and Mg2SiO4 (forsterite). The study also detected water vapor in the atmosphere in the form of a dip at 1.4 μm. The dayside temperature was measured to be 2,260+40−50 K and the nightside temperature was measured to be <1,330 K. However, a pure cloudy atmosphere is inconsistent with the results of a 2025 study, which indicates that some mixing processes might have affected the atmospheric composition of LTT 9779 b. Another study in 2025 confirms the planet has a metal-rich atmosphere and also suggest it likely has silicate (MgSiO3) clouds.

Name LTT 9779 b was officially named Cuancoá in 2022 by the International Astronomical Union, as part of the NameExoWorlds competition. Cuancoá is a word that refers to the morning star in the Uwa language (Tunebo). Cuancoá's star was named Uúba after the word for 'star', 'seed', and 'eye' in the same language.

See also List of proper names of exoplanets Neptunian desert NGTS-4b, another planet in the Neptunian desert

References

Worked examples

Example 1 — a first encounter with LTT 9779 b

Start with the simplest possible case. Write down what LTT 9779 b 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 LTT 9779 b 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 LTT 9779 b 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 LTT 9779 b

In research: LTT 9779 b 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 LTT 9779 b 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: LTT 9779 b is common in secondary-school and first-year university syllabi. It links to neighbouring topics Exoplanets discovered by TESS, Exoplanets discovered in 2020, Exoplanets with proper names, so understanding it makes those chapters shorter.
In everyday life: Look for LTT 9779 b 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 LTT 9779 b in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what LTT 9779 b 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 LTT 9779 b out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is LTT 9779 b in simple terms?

LTT 9779 b, officially named Cuancoá, is a Neptune-sized planet orbiting the sunlike star LTT 9779, or Uúba. As of 2023, it has the highest-known albedo of any planet.

Why does LTT 9779 b 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 LTT 9779 b?

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 LTT 9779 b.