astronomy

Tau1 Gruis

Tau1 Gruis 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 Gruis rather than just read about it. In short: Tau1 Gruis, Latinized from τ1 Gruis, and catalogued as HD 216435 and HR 8700, is a yellow-hued star approximately 108 light-years away in the constellation of Grus (the Crane). The star is visible to the naked eye for some people, placing it in the Bright Star Catalogue.

Key takeaways

Tau1 Gruis 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 Gruis to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Tau1 Gruis from memory before moving on to harder problems.

Reference excerpt

Tau1 Gruis, Latinized from τ1 Gruis, and catalogued as HD 216435 and HR 8700, is a yellow-hued star approximately 108 light-years away in the constellation of Grus (the Crane). The star is visible to the naked eye for some people, placing it in the Bright Star Catalogue. In 2002, one extrasolar planet was confirmed to orbit the star.

Characteristics Tau1 Gruis is a G-type main-sequence star of spectral type G0 V. It is estimated that the star has about 1.28 times the mass of the Sun, 1.71 times the Sun's radius, and about 3.6 times the luminosity. Due to its unusual brightness, at least one source suspects that the star may be a highly evolved subgiant star. It is thought that Tau1 Gruis is about 1.4 times more enriched with elements heavier than hydrogen, making a high abundance of iron likely. The Ca-II H line of the star suggests that it is chromospherically inactive, making it significantly older than previously predicted.

Planetary system On September 17, 2002, a team of astronomers led by Geoffrey Marcy announced the discovery of a giant planet around Tau1 Gruis. The radial velocity measurements suggest that the star has a companion with at least 1.23 times the mass of Jupiter. The planet's orbit stays inside the system's habitable zone for most of its revolution around the star, though at apoapsis, the planet falls outside of this zone.

See also Rho Indi 55 Cancri Phi2 Pavonis

References

External links "Notes for star HD 216435". Extrasolar Planets Encyclopaedia. Archived from the original on September 26, 2007. Retrieved 2008-06-22. "Tau1 Gruis". Solstation. Archived from the original on October 20, 2002. Retrieved 2008-06-22.

Illustrations

Worked examples

Example 1 — a first encounter with Tau1 Gruis

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

In research: Tau1 Gruis 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 Gruis 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 Gruis 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 Gruis 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 Gruis in 20 minutes

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

Frequently asked questions

What is Tau1 Gruis in simple terms?

Why does Tau1 Gruis 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 Gruis?

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 Gruis.