astronomy

HD 93083

HD 93083 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 93083 rather than just read about it. In short: HD 93083 (or GJ 1137) is an orange-hued star in the southern constellation of Antlia. It has the proper name Macondo, after the mythical village of the novel One Hundred Years of Solitude (Cien años de soledad).

Key takeaways

HD 93083 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 93083 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 93083 from memory before moving on to harder problems.

Reference excerpt

HD 93083 (or GJ 1137) is an orange-hued star in the southern constellation of Antlia. It has the proper name Macondo, after the mythical village of the novel One Hundred Years of Solitude (Cien años de soledad). The name was selected by Colombia during the IAU's NameExoWorlds campaign. The star has an apparent visual magnitude of 8.30, which is too faint to be visible to the naked eye. It is located at a distance of 93 light-years from the Sun based on parallax. HD 93083 is drifting further away with a radial velocity of +43.65 km/s, having come to within 43 light-years some 484,000 years ago. This is a K-type main-sequence star that has been assigned a stellar classification of K2IV-V or K3V, depending on the study. It is smaller and less massive than the Sun, with a higher metallicity, or abundance of elements heavier than helium. The star is roughly six billion years old with a low projected rotational velocity of 2.2 km/s, and has an expected main sequence lifetime of 20.4 billion years. It is a source of X-ray emission with a luminosity of 7.9×1026 erg s−1. The star is radiating around 41% of the luminosity of the Sun from its photosphere at an effective temperature of 5,030 K.

Planetary system In 2005, the discovery of a Saturn-mass exoplanet orbiting the star was announced. This was a discovery using the radial velocity method with the HARPS spectrograph. The planet was given the name Melquíades by the IAU in 2019 after a character in the book One Hundred Years of Solitude. The orbit of this body is in or near the habitable zone of the host star; according to a 2007 study, it is entirely within the habitable zone, but more recent models place it near the inner edge. It is theoretically possible that a large moon orbiting the planet, or a hypothetical terrestrial exoplanet at a trojan point, could be habitable. A second planet was found in 2026, also with HARPS radial velocity observations. It is a super-Earth at least 5 times Earth's mass, orbiting with a short period of 9.6 days. Another long-period radial velocity signal is due to the star's magnetic activity cycle rather than a planet.

See also List of extrasolar planets HARPS spectrograph

References

Further reading Saffe, C.; et al. (2005). "On the Ages of Exoplanet Host Stars". Astronomy and Astrophysics. 443 (2): 609–626. arXiv:astro-ph/0510092. Bibcode:2005A&A...443..609S. doi:10.1051/0004-6361:20053452. S2CID 11616693.

Worked examples

Example 1 — a first encounter with HD 93083

Start with the simplest possible case. Write down what HD 93083 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 93083 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 93083 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 93083

In research: HD 93083 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 93083 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 93083 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Antlia, Durchmusterung objects, Gliese and GJ objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 93083 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 93083 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 93083 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 93083 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 93083 in simple terms?

Why does HD 93083 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 93083?

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 93083.