astronomy

NY Virginis

NY Virginis 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 NY Virginis rather than just read about it. In short: NY Virginis is a binary star about 1,940 light-years away. The primary belongs to the rare class of subdwarf B stars, being former red giants with their hydrogen envelope completely stripped by a stellar companion.

Key takeaways

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

Reference excerpt

NY Virginis is a binary star about 1,940 light-years away. The primary belongs to the rare class of subdwarf B stars, being former red giants with their hydrogen envelope completely stripped by a stellar companion. The companion is a red dwarf star. The eclipsing binary nature of NY Virginis was first identified in 1998, and the extremely short orbital period of 0.101016 d, together with brightness variability on the timescale of 200 seconds was noticed, resulting in the identification of the primary star as a B-type subdwarf in 2003. Under a proposed classification scheme for hot subdwarfs it would be class sdB1VII:He1. This non-standard system indicates that it is a "normal" luminosity for a hot subdwarf and that the spectrum is dominated by hydrogen rather than helium.

Planetary system In 2011, variations in the timing of the binary star's eclipses were used to infer the presence of a superjovian planet, NY Virginis (AB) b, on a wide orbit, with a second planet being suspected. A study in 2014 found that a two-planet model was preferred. The orbits of these two planets are near or at a 3:10 mutual orbital resonance. Another two-planet model with significant orbital eccentricity, updated to account for changes in eclipse timing not predicted by previous models, was published in 2019. Studies in 2022 have noted that since planetary models generally fail to predict subsequent changes in eclipse timing, and the most recent two-planet model as of 2021 results in orbits that are unstable on an astronomically-short timescale. However, in 2023 another model with circular orbits was proposed, which gives stability to the system. The same team also find that it is valid that there are exoplanets in the system creating the eclipe timing variations, and that the moderate eccentricites of the previous model likely caused the orbital instability. In 2025 it was found that all models fail to predict new changes in eclipse timing. While this does not rule out the existence of the planets, it is possible that multiple mechanisms are responsible for the ETVs.

References

Illustrations

Worked examples

Example 1 — a first encounter with NY Virginis

Start with the simplest possible case. Write down what NY Virginis 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 NY Virginis 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 NY Virginis 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 NY Virginis

In research: NY Virginis 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 NY Virginis 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: NY Virginis is common in secondary-school and first-year university syllabi. It links to neighbouring topics Algol variables, B-type subdwarfs, M-type main-sequence stars, so understanding it makes those chapters shorter.
In everyday life: Look for NY Virginis 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 NY Virginis in 20 minutes

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

Frequently asked questions

What is NY Virginis in simple terms?

Why does NY Virginis 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 NY Virginis?

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 NY Virginis.