astronomy

YSES 1

YSES 1 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 YSES 1 rather than just read about it. In short: YSES 1, also known as TYC 8998-760-1, is a pre-main-sequence star located 310 light years away from Earth in the constellation of Musca, with a mass 1.00±0.02 times the Sun. Planetary system There are two giant substellar bodies orbiting the star.

Key takeaways

YSES 1 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect YSES 1 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of YSES 1 from memory before moving on to harder problems.

Reference excerpt

YSES 1, also known as TYC 8998-760-1, is a pre-main-sequence star located 310 light years away from Earth in the constellation of Musca, with a mass 1.00±0.02 times the Sun.

Planetary system There are two giant substellar bodies orbiting the star. In 2020, the European Southern Observatory's Very Large Telescope photographed the two bodies using its SPHERE instrument, producing the first direct image of multiple bodies orbiting a Sun-like star.

YSES 1 b YSES 1 b is the inner companion, orbiting at 146 AU (2.18×1010 km; 1.36×1010 mi) from the host star, or slightly more than 5 times the Neptune-Sun distance. Its mass was initially estimated at 14 MJ based on an age of 15 Myr and later at 21.8 MJ based on an age of 27 Myr. The planetary parameters were revised in 2026, resulting in two mass values of 25.7+4.1−3.6 and 41.6+3.6−3.4 MJ, depending on the age. These revised values put YSES 1 b within the brown dwarf regime. In July 2021, astronomers reported the detection, for the first time, of an isotope in the atmosphere of an exoplanet; more specifically, the isotope Carbon-13 (C13) was found in the atmosphere. This was later confirmed with VLT/CRIRES+. This spectrum showed that the atmosphere is dominated by water vapor and carbon monoxide. The researchers also detect hydrogen fluoride in the atmosphere. The object is an L-dwarf with a spectral type of L0. Observations with the James Webb Space Telescope detected silicate emission from YSES 1b, indicating the presence of a circumplanetary disk. The emission was attributed to submicron olivine dust grains. These very small and hot grains might have formed from collisions of satellites forming inside the circumplanetary disk. Observations with VLT MUSE revealed emission by hydrogen (Hα, Hβ), calcium (H+K lines) and helium, coming from YSES 1b. These lines are attributed to accretion of material from the circumplanetary disk to the surface of the planet. It is the first object in this mass range with these full combination of lines. The planet accretes between 1.11 × 10−9±0.19 MJ/yr and 1.45 × 10−9±0.19 MJ/yr (or the mass equivalent of at least 21 Lutetia per year).

YSES 1 c YSES 1 c is a substellar object with a mass of 7.2 MJ, and orbits at 320 AU (4.8×1010 km; 3.0×1010 mi), or slightly more than 11 times the Neptune-Sun distance. Atmospheric water vapor and carbon monoxide was detected with VLT/CRIRES+. The object is of spectral class L7.5. Additionally, JWST spectra with NIRSpec and MIRI were published. The spectrum of YSES 1 c does show direct detection of silicate clouds.

References

Illustrations

Worked examples

Example 1 — a first encounter with YSES 1

Start with the simplest possible case. Write down what YSES 1 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 YSES 1 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 YSES 1 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 YSES 1

In research: YSES 1 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 YSES 1 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: YSES 1 is common in secondary-school and first-year university syllabi. It links to neighbouring topics K-type main-sequence stars, Musca, Planetary systems with two confirmed planets, so understanding it makes those chapters shorter.
In everyday life: Look for YSES 1 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 YSES 1 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what YSES 1 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 YSES 1 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is YSES 1 in simple terms?

YSES 1, also known as TYC 8998-760-1, is a pre-main-sequence star located 310 light years away from Earth in the constellation of Musca, with a mass 1.00±0.02 times the Sun. Planetary system There are two giant substellar bodies orbiting the star.

Why does YSES 1 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 YSES 1?

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 YSES 1.