astronomy

GJ 3512

GJ 3512 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 3512 rather than just read about it. In short: GJ 3512 is a nearby star in the northern circumpolar constellation of Ursa Major. It is invisible to the naked eye but can be observed using a telescope, having an apparent visual magnitude of +15.05.

Key takeaways

GJ 3512 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 3512 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of GJ 3512 from memory before moving on to harder problems.

Reference excerpt

GJ 3512 is a nearby star in the northern circumpolar constellation of Ursa Major. It is invisible to the naked eye but can be observed using a telescope, having an apparent visual magnitude of +15.05. The star is located at a distance of 31 light-years from the Sun based on parallax. It has a high proper motion, traversing the celestial sphere at the rate of 1.311″ yr−1. The measurement of the star's radial velocity is poorly constrained, but it appears to be drifting further away at a rate of ~8 km/s. The stellar classification of GJ 3512 is dM5.5, which determines this to be a small red dwarf star that is generating energy through core hydrogen fusion. It displays a moderate amount of magnetic activity with a Sun-like cycle lasting 14 years. A low-level variability lasting ~87 d matches the approximate rotation period. The star has 12.5% of the mass of the Sun and 16% of the Sun's radius. It is radiating 1.6% of the luminosity of the Sun from its photosphere at an effective temperature of 3,081 K.

Planetary system A gas giant planet in an eccentric orbit around GJ 3512 was discovered in 2019 utilizing the radial velocity method. The star's mass is only 250 times that of the gas giant, calling into question traditional models of planetary formation. If the star was born in an open cluster, this planet may instead have formed around a higher-mass star then been swapped into this system during an interaction. The eccentric orbit of this object may have been caused by the ejection of another exoplanet from the system. A second gas giant planet on a wider, circular orbit is suspected; a 2020 study provided stronger evidence for this planet, and it is now considered confirmed by most sources.

See also List of star systems within 30–35 light-years

References

External links "Planet GJ 3512 b". Extrasolar Planets Encyclopaedia. 1995. Retrieved 2020-12-19.

Worked examples

Example 1 — a first encounter with GJ 3512

Start with the simplest possible case. Write down what GJ 3512 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 3512 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 3512 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 3512

In research: GJ 3512 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 3512 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 3512 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Gliese and GJ objects, M-type main-sequence stars, Planetary systems with two confirmed planets, so understanding it makes those chapters shorter.
In everyday life: Look for GJ 3512 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 3512 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what GJ 3512 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 3512 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is GJ 3512 in simple terms?

Why does GJ 3512 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 3512?

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 3512.