astronomy

GJ 1289

GJ 1289 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 GJ 1289 rather than just read about it. In short: GJ 1289 is a red dwarf star located approximately 27 light-years from the Sun in the constellation Andromeda. It is a single star of spectral class M4.5 V, with about 21% of the Sun's mass.

Key takeaways

GJ 1289 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect GJ 1289 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of GJ 1289 from memory before moving on to harder problems.

Reference excerpt

GJ 1289 is a red dwarf star located approximately 27 light-years from the Sun in the constellation Andromeda. It is a single star of spectral class M4.5 V, with about 21% of the Sun's mass. The star hosts at least one confirmed exoplanet, GJ 1289 b, and is fully convective, making it a target for studying planetary formation around low-mass stars. Despite its slow rotation, GJ 1289 exhibits large-scale magnetic field strengths similar to those of faster-rotating M dwarfs, suggesting that the star operates a dynamo process in a regime distinct from more rapidly rotating stars. The star is predominantly poloidal with its magnetic topology varying over time, and their small-scale fields contribute more than 70% of the star's overall magnetic flux.

References

Worked examples

Example 1 — a first encounter with GJ 1289

Start with the simplest possible case. Write down what GJ 1289 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 GJ 1289 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 GJ 1289 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 GJ 1289

In research: GJ 1289 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 GJ 1289 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: GJ 1289 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Andromeda (constellation), Gliese and GJ objects, M-type main-sequence stars, so understanding it makes those chapters shorter.
In everyday life: Look for GJ 1289 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 GJ 1289 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what GJ 1289 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 GJ 1289 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is GJ 1289 in simple terms?

GJ 1289 is a red dwarf star located approximately 27 light-years from the Sun in the constellation Andromeda. It is a single star of spectral class M4.5 V, with about 21% of the Sun's mass.

Why does GJ 1289 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 GJ 1289?

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 GJ 1289.