astronomy

Upsilon Orionis

Upsilon Orionis 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 Upsilon Orionis rather than just read about it. In short: Upsilon Orionis (υ Ori, υ Orionis) is a star in the constellation Orion. It has the traditional name Thabit or Tabit (ﺛﺎﺑﺖ, Arabic for "the endurer"), a name shared with Pi3 Orionis.

Key takeaways

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

Reference excerpt

Upsilon Orionis (υ Ori, υ Orionis) is a star in the constellation Orion. It has the traditional name Thabit or Tabit (ﺛﺎﺑﺖ, Arabic for "the endurer"), a name shared with Pi3 Orionis. It is a blue-white main sequence star of apparent magnitude 4.62 located over 1,300 light-years distant from the Solar System. It is a suspected Beta Cephei variable.

Name Located south of Iota Orionis, Upsilon Orionis is one of two stars (the other is 29 Orionis) marking the top of Orion's right boot in Johann Bayer's Uranometria (1603). It was given the number 36 by John Flamsteed, while its proper name appears to be derived from the Arabic Al Thabit "the endurer". In his Star-Names and Their Meanings (1899), American amateur naturalist Richard Hinckley Allen noted that the name appeared on the star atlas Geography of the Heavens, composed by Elijah Hinsdale Burritt, but its ultimate origin was unknown.

Properties Since 1943, this star has been consistently defined as a B0 main sequence star used as a reference for classifying the spectra of other stars on the MK scale, although in other studies it has been classified as O9V and O9.5V. The Galactic O-Star Spectroscopic Survey defined it as the standard star for the O9.7V spectral type in 2011. In a 1981 paper, Thabit was observed to have nonradial pulsations over a period of around 12 hours, and has been classified as a slowly pulsating B star. Subsequent review of Hipparcos catalog data indicated it was most likely a Beta Cephei variable, and is hence considered a candidate for that class. These are blue-white main sequence stars of around 10 to 20 times the mass of the Sun that pulsate with periods of 0.1 to 0.3 days; their changes in magnitude are much more pronounced in the ultraviolet than in the visual spectrum. It is classified as a Beta Cephei variable by the American Association of Variable Star Observers, and has an apparent magnitude of +4.62. Thabit's parallax has been measured at 2.46±0.14 mas, yielding a distance of approximately 1,325 light years from Earth. Spectroscopic observations found it to be 1,260 light-years distant, with a radius 5.5 and a luminosity 32,000 that of the Sun, an effective temperature of 32,900 K and a mass 17.5 that of the Sun. It is one of the most massive stars of the Orion OB1c association (in Orion's Sword).

Notes

References

Illustrations

Worked examples

Example 1 — a first encounter with Upsilon Orionis

Start with the simplest possible case. Write down what Upsilon Orionis 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 Upsilon Orionis 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 Upsilon Orionis 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 Upsilon Orionis

In research: Upsilon Orionis 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 Upsilon Orionis 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: Upsilon Orionis is common in secondary-school and first-year university syllabi. It links to neighbouring topics B-type main-sequence stars, Bayer objects, Beta Cephei variables, so understanding it makes those chapters shorter.
In everyday life: Look for Upsilon Orionis 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.

Affiliate

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

How to study Upsilon Orionis in 20 minutes

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

Frequently asked questions

What is Upsilon Orionis in simple terms?

Upsilon Orionis (υ Ori, υ Orionis) is a star in the constellation Orion. It has the traditional name Thabit or Tabit (ﺛﺎﺑﺖ, Arabic for "the endurer"), a name shared with Pi3 Orionis.

Why does Upsilon Orionis 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 Upsilon Orionis?

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 Upsilon Orionis.