astronomy

HE 0107−5240

HE 0107−5240 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 HE 0107−5240 rather than just read about it. In short: HE 0107−5240 is a binary star system in the constellation of Phoenix, consisting of extremely metal-poor Population II stars. It is located roughly 6,930 parsecs (22,600 light-years) away from Earth.

Key takeaways

HE 0107−5240 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HE 0107−5240 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HE 0107−5240 from memory before moving on to harder problems.

Reference excerpt

HE 0107−5240 is a binary star system in the constellation of Phoenix, consisting of extremely metal-poor Population II stars. It is located roughly 6,930 parsecs (22,600 light-years) away from Earth. This system is one of the most metal-poor known in our Galaxy, with a metallicity [Fe/H] = −5.2±0.2; i.e. it has just ⁠1/160000⁠ of the metal that the Sun has. Because of its very low metallicity, it is believed to be one of the earliest Population II stars to have formed. If so, then it is also very old, with an age of roughly 13 billion years. Because the stars are not completely metal-free, they do not belong to the first generation of stars (the hypothetical Population III). Pop III stars converted the pristine hydrogen, helium, and lithium formed by the Big Bang into heavier elements, such as carbon, oxygen, and metals. HE0107−5240 was found by Norbert Christlieb and colleagues at the University of Hamburg in Germany as a byproduct of the Hamburg/ESO Survey for faint quasars with the 1m ESO Schmidt telescope. Follow-up observations were made at the Siding Spring 2.3 m Telescope and high-resolution spectra were taken at the European Southern Observatory in Chile, using one of the units of the Very Large Telescope. In 2005, a second star with an even smaller iron abundance, HE 1327-2326 ([Fe/H]=-5.4), was found, also in the Hamburg/ESO survey. In 2014 an even more metal poor star was announced: SMSS J031300.36−670839.3. In 2020, HE 0107−5240 was revealed to be an spectroscopic binary system. The orbit has a period of 10,560 days (28.9 years) and a low eccentricity. The companion has a mass of at least 0.14 solar masses.

See also Other ultra low metallicity / ultra metal poor stars

Cayrel's Star HE 1327−2326 SDSS J102915+172927

Notes

References

Christlieb N., Bessell M.S., Gustafsson B., Korn A., Barklem P.S., Karisson T., Mizuno-Wiedner M., Rossi S., "A stellar relic from the early Milky Way", Nature, 419, 904-906 (2002)

External links SIMBAD-Entry (SIMBAD) Hamburg/ESO survey (Christlieb+, 2008) Relic Star Found, Pointing Way to Dawn of Time (Space.com) VLT UVES Observes Most Metal-Deficient Star Known (European Southern Observatory) he0107-5240

Illustrations

Worked examples

Example 1 — a first encounter with HE 0107−5240

Start with the simplest possible case. Write down what HE 0107−5240 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 HE 0107−5240 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 HE 0107−5240 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 HE 0107−5240

In research: HE 0107−5240 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 HE 0107−5240 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: HE 0107−5240 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Phoenix (constellation), Population II stars, so understanding it makes those chapters shorter.
In everyday life: Look for HE 0107−5240 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 HE 0107−5240 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HE 0107−5240 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 HE 0107−5240 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HE 0107−5240 in simple terms?

Why does HE 0107−5240 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 HE 0107−5240?

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 HE 0107−5240.