astronomy

Tau1 Eridani

Tau1 Eridani 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 Tau1 Eridani rather than just read about it. In short: Tau1 Eridani, Latinized from τ1 Eridani, is a binary star system in the constellation Eridanus. It has an apparent magnitude of 4.46, making it visible to the naked eye in suitably dark conditions.

Key takeaways

Tau1 Eridani belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Tau1 Eridani to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tau1 Eridani from memory before moving on to harder problems.

Reference excerpt

Tau1 Eridani, Latinized from τ1 Eridani, is a binary star system in the constellation Eridanus. It has an apparent magnitude of 4.46, making it visible to the naked eye in suitably dark conditions. This is a spectroscopic binary with an orbital period of 958 days. It is located about 46 light years from the Earth. At present, the system is moving away from the Sun with a radial velocity of +26 km/s. About 305,000 years ago, perihelion passage was made at an estimated distance of 30.5 ly (9.35 pc). Tau1 Eridani was a latter designation of 90 Ceti.

Debris disk A moderate far-infrared excess was observed for this star system, in the 12μm, 25μm, 60μm and 100μm wavelengths, by the Infrared Astronomical Satellite (IRAS), and published in 1993. This discovery was subsequently interpreted as indicating a debris disk with a radius near 500 AU. It was further speculated that, if the star system had been observed at longer wavelengths, it was likely the debris disk would have been seen to have a radius considerably wider than 500 AU. Later observations made by the Spitzer Space Telescope, published in 2004, detected no substantial infrared excess around the stars, within the 14-35μm range of wavelengths.

References

Illustrations

Worked examples

Example 1 — a first encounter with Tau1 Eridani

Start with the simplest possible case. Write down what Tau1 Eridani 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 Tau1 Eridani 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 Tau1 Eridani 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 Tau1 Eridani

In research: Tau1 Eridani 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 Tau1 Eridani 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: Tau1 Eridani is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bayer objects, Bright Star Catalogue objects, Durchmusterung objects, so understanding it makes those chapters shorter.
In everyday life: Look for Tau1 Eridani 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 Tau1 Eridani in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Tau1 Eridani 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 Tau1 Eridani out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Tau1 Eridani in simple terms?

Tau1 Eridani, Latinized from τ1 Eridani, is a binary star system in the constellation Eridanus. It has an apparent magnitude of 4.46, making it visible to the naked eye in suitably dark conditions.

Why does Tau1 Eridani 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 Tau1 Eridani?

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 Tau1 Eridani.