astronomy

Psi Ursae Majoris

Psi Ursae Majoris 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 Psi Ursae Majoris rather than just read about it. In short: Psi Ursae Majoris (Psi UMa, ψ Ursae Majoris, ψ UMa) is a star in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of +3.01, making it a third magnitude star and one of the brighter members of the constellation.

Key takeaways

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

Reference excerpt

Psi Ursae Majoris (Psi UMa, ψ Ursae Majoris, ψ UMa) is a star in the northern circumpolar constellation of Ursa Major. It has an apparent visual magnitude of +3.01, making it a third magnitude star and one of the brighter members of the constellation. Parallax measurements place it at a distance of 140 light-years (43 parsecs) from Earth. This is sufficiently close that the magnitude of the star is only reduced by 0.05 due to extinction. In Chinese astronomy, Psi Ursae Majoris is called 太尊, Pinyin: Tàizūn, meaning Royals, because this star stands alone as the only member of the Royals asterism within the Purple Forbidden enclosure (see Chinese constellation). In R. H. Allen's Star Names, this was transliterated as Tien Tsan or Ta Tsun, meaning "Extremely Honorable". The spectrum of this star matches a stellar classification of K1 III, with the luminosity class of 'III' indicating this is an evolved giant star that has exhausted the supply of hydrogen at its core. As a consequence, it has expanded to around 20 times the radius of the Sun. It is radiating roughly 140 times the luminosity of the Sun from its enlarged outer envelope at an effective temperature of 4,543 K. At this heat, the star glows with the orange hue of a K-type star. Psi Ursae Majoris is a member of the thin disk population of the Milky Way. It is following an orbit through the galaxy with a low eccentricity of 0.02 that will carry it between 26.5–27.8 kly (8.1–8.5 kpc) from the Galactic Center. The low inclination of its orbit means the star will only stray 130 ly (40 pc) from the galactic plane.

References

Worked examples

Example 1 — a first encounter with Psi Ursae Majoris

Start with the simplest possible case. Write down what Psi Ursae Majoris 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 Psi Ursae Majoris 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 Psi Ursae Majoris 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 Psi Ursae Majoris

In research: Psi Ursae Majoris 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 Psi Ursae Majoris 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: Psi Ursae Majoris is common in secondary-school and first-year university syllabi. It links to neighbouring topics Bayer objects, Bright Star Catalogue objects, Durchmusterung objects, so understanding it makes those chapters shorter.
In everyday life: Look for Psi Ursae Majoris 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 “Psi Ursae Majoris” →

Affiliate

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

How to study Psi Ursae Majoris in 20 minutes

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

Frequently asked questions

What is Psi Ursae Majoris in simple terms?

Why does Psi Ursae Majoris 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 Psi Ursae Majoris?

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 Psi Ursae Majoris.