science

G 240-72

G 240-72 is a science 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 G 240-72 rather than just read about it. In short: G 240-72 (or WD 1748+708, or LHS 455, or GJ 1221) is a nearby white dwarf (degenerate star) of spectral class DQP9.0, located 20.3 light-years away in the constellation Draco. Distance G 240-72 is the seventh closest white dwarf (after Sirius B, Procyon B, van Maanen's star, Gliese 440, 40 Eridani B and Stein 2051 B).

Key takeaways

G 240-72 belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect G 240-72 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of G 240-72 from memory before moving on to harder problems.

Reference excerpt

G 240-72 (or WD 1748+708, or LHS 455, or GJ 1221) is a nearby white dwarf (degenerate star) of spectral class DQP9.0, located 20.3 light-years away in the constellation Draco.

Distance G 240-72 is the seventh closest white dwarf (after Sirius B, Procyon B, van Maanen's star, Gliese 440, 40 Eridani B and Stein 2051 B). Its trigonometric parallax, as measured by the Gaia space telescope, is 160.9952±0.0119 mas, corresponding to a distance of 6.2114 parsecs (20.259 light-years).

Properties G 240-72 has a mass of 0.81 Solar masses and surface gravity 108.36 (2.29×108) cm·s−2, or approximately 234 000 of Earth's, corresponding to a radius 6850 km, or 107% of Earth's. This white dwarf has a relatively low temperature of 5590 K (slightly cooler than the Sun), and an old cooling age, i.e. the age as a degenerate star (not counting the duration of its previous existence as a main sequence and giant star) of 5.69 Gyr. It has a white appearance, due to its similar temperature to the Sun. It has a pure helium atmosphere and rotates very slowly, with period of possibly over 100 years.

References

Notes

External links The 100 Nearest Star Systems (RECONS)

Worked examples

Example 1 — a first encounter with G 240-72

Start with the simplest possible case. Write down what G 240-72 claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, 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 G 240-72 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 G 240-72 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 G 240-72

In research: G 240-72 appears in science 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 G 240-72 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: G 240-72 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Draco (constellation), Gliese and GJ objects, White dwarfs, so understanding it makes those chapters shorter.
In everyday life: Look for G 240-72 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 G 240-72 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what G 240-72 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 G 240-72 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is G 240-72 in simple terms?

G 240-72 (or WD 1748+708, or LHS 455, or GJ 1221) is a nearby white dwarf (degenerate star) of spectral class DQP9.0, located 20.3 light-years away in the constellation Draco. Distance G 240-72 is the seventh closest white dwarf (after Sirius B, Procyon B, van Maanen's star, Gliese 440, 40 Eridani…

Why does G 240-72 matter?

Because it connects several science 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 G 240-72?

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 G 240-72.