astronomy

HD 89307

HD 89307 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 89307 rather than just read about it. In short: HD 89307 is a star in the equatorial constellation of Leo. It is too faint to be viewed with the naked eye except under ideal conditions, having an apparent visual magnitude of 7.02.

Key takeaways

HD 89307 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 89307 to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of HD 89307 from memory before moving on to harder problems.

Reference excerpt

HD 89307 is a star in the equatorial constellation of Leo. It is too faint to be viewed with the naked eye except under ideal conditions, having an apparent visual magnitude of 7.02. The star is located at a distance of 104 light-years (32 parsecs) from the Sun based on parallax, and is drifting further away with a radial velocity of +23 km/s. This is an ordinary G-type main-sequence star with a stellar classification of G0V. It is chromospherically inactive and appears older than the Sun with a rotation period of 23.7 days. The star has about the same mass as the Sun and is 8% larger. It is radiating 1.35 times the Sun's luminosity from its photosphere at an effective temperature of 5,950 K.

Planetary system In December 2004, using the radial velocity method, it was found to have a long-period giant planet in orbit around it. The parameters of HD 89307 b were updated in 2012, and in 2023 its inclination and true mass were determined via astrometry.

See also List of extrasolar planets List of stars in Leo

References

External links "Notes for star HD 89307". Extrasolar Planets Encyclopaedia. Archived from the original on November 6, 2007. Retrieved 2008-08-18.

Worked examples

Example 1 — a first encounter with HD 89307

Start with the simplest possible case. Write down what HD 89307 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 89307 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 89307 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 89307

In research: HD 89307 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 89307 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 89307 is common in secondary-school and first-year university syllabi. It links to neighbouring topics Durchmusterung objects, G-type main-sequence stars, Henry Draper Catalogue objects, so understanding it makes those chapters shorter.
In everyday life: Look for HD 89307 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.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “HD 89307” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study HD 89307 in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what HD 89307 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 89307 out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is HD 89307 in simple terms?

HD 89307 is a star in the equatorial constellation of Leo. It is too faint to be viewed with the naked eye except under ideal conditions, having an apparent visual magnitude of 7.02.

Why does HD 89307 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 89307?

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 89307.