astronomy

HD 159062

HD 159062 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 HD 159062 rather than just read about it. In short: HD 159062 is a spectroscopic binary consisting of a Sun-like star and a white dwarf positioned in the northern constellation of Hercules. With an apparent magnitude of 7.305, it is too faint to be seen by the naked eye but is readily visible via binoculars.

Key takeaways

HD 159062 belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect HD 159062 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 159062 from memory before moving on to harder problems.

Reference excerpt

HD 159062 is a spectroscopic binary consisting of a Sun-like star and a white dwarf positioned in the northern constellation of Hercules. With an apparent magnitude of 7.305, it is too faint to be seen by the naked eye but is readily visible via binoculars. It is located at a distance of 70.619 light-years (21.652 parsecs) according to parallax calculations, and is approaching the Solar System at a heliocentric radial velocity of −83.980 km/s.

Stellar properties The primary star, designated HD 159062 A, is a G-type main-sequence star slightly cooler than the Sun with 80% the mass and 76% the radius. It has the spectral type G9V Fe−0.8, where the "Fe−0.8" suffix indicates a slight but anomalous deficiency of metals like iron. Indeed, it has a low metallicity of [Fe/H]=−0.31±0.06 dex. The star is thought to be ancient, somewhere between 9-13 billion years old, and has been marked as a population II star and a candidate blue straggler. It rotates on its axis at roughly 2 km/s, about the same as the Sun's equatorial rotational velocity (1.997 km/s). Based on stellar kinematics, it is very likely (88% probability) a part of the thick disk population, and has been measured to have a europium abundance typical of thick disk stars. However, it is highly enhanced in s-process elements, such as barium, lanthanum, and cerium. Fuhrmann et al. (2017) noted that the barium overabundance is particularly extreme at [Ba/Fe]=0.40 dex, which they argued was almost certainly the result of stellar wind accretion from a distant (orbital period 10-1,000 years) former asymptotic giant branch primary, which would have shriveled up into a cool white dwarf companion. As predicted, a white dwarf, HD 159062 B, was discovered in 2019 by Hirsch et al. in a near-circular orbit around HD 159062 A at a distance of approximately 62 AU with a period of 411 years. The low eccentricity and large separation of the orbit implies that a Roche lobe overflow never took place. It was once a ~1.5 M☉ star, whose lifespan came to an end roughly 8 billion years ago and has been radiating away heat as a stellar remnant ever since. It has now cooled to an effective temperature of 4,580 K (4,310 °C; 7,780 °F). Its mass, together with its orbital parameters, was determined precisely using a Python script devised in 2021.

See also List of star systems within 70–75 light-years

References

Illustrations

Worked examples

Example 1 — a first encounter with HD 159062

Start with the simplest possible case. Write down what HD 159062 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 HD 159062 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 HD 159062 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 HD 159062

In research: HD 159062 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 HD 159062 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: HD 159062 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Binary stars, Durchmusterung objects, G-type main-sequence stars, so understanding it makes those chapters shorter.
In everyday life: Look for HD 159062 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 HD 159062 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 159062 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 HD 159062 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 159062 in simple terms?

Why does HD 159062 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 HD 159062?

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 HD 159062.