astronomy

Sigma Piscium

Sigma Piscium 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 Sigma Piscium rather than just read about it. In short: Sigma Piscium (Sigma Psc, σ Piscium, σ Psc) is a binary star in the zodiac constellation of Pisces. It has an apparent magnitude of +5.50, meaning it is barely visible to the naked eye, according to the Bortle scale.

Key takeaways

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

Reference excerpt

Sigma Piscium (Sigma Psc, σ Piscium, σ Psc) is a binary star in the zodiac constellation of Pisces. It has an apparent magnitude of +5.50, meaning it is barely visible to the naked eye, according to the Bortle scale. While parallax measurements by the Hipparcos spacecraft give a distance of approximately 430 light years (133 parsecs), dynamical parallax measurements put it slightly closer, at 368 light-years (113 parsecs) from Earth. Sigma Piscium is a spectroscopic binary system, meaning the components of the system have been detected from periodic Doppler shifts in their spectra. In this case, light from both stars can be detected and it is double-lined. It has an orbital period of 81 days, and the orbit is relatively eccentric, at about 0.9. Both components are B-type main-sequence stars. Sigma Piscium is moving through the Milky Way at a speed of 23.5 km/s relative to the Sun. Its projected galactic orbit carries it between 24,300 and 29,400 light years from the center of the galaxy. Sigma Piscium was a latter designation of 40 Andromedae.

Naming In Chinese, 奎宿 (Kuí Sù), meaning Legs, refers to an asterism consisting of σ Piscium, η Andromedae, 65 Piscium, ζ Andromedae, ε Andromedae, δ Andromedae, π Andromedae, ν Andromedae, μ Andromedae, β Andromedae, τ Piscium, 91 Piscium, υ Piscium, φ Piscium, χ Piscium and ψ1 Piscium. Consequently, the Chinese name for σ Piscium itself is 奎宿十 (Kuí Sù shí, English: the Tenth Star of Legs.) Sigma Piscium, however, is also identified with Kuísùzēngshíwǔ (奎宿增十五), the 15th additional star in the Legs asterism.

References

Illustrations

Worked examples

Example 1 — a first encounter with Sigma Piscium

Start with the simplest possible case. Write down what Sigma Piscium 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 Sigma Piscium 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 Sigma Piscium 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 Sigma Piscium

In research: Sigma Piscium 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 Sigma Piscium 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: Sigma Piscium is common in secondary-school and first-year university syllabi. It links to neighbouring topics B-type main-sequence stars, Bayer objects, Bright Star Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for Sigma Piscium 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 Sigma Piscium in 20 minutes

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

Frequently asked questions

What is Sigma Piscium in simple terms?

Why does Sigma Piscium 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 Sigma Piscium?

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 Sigma Piscium.