Alpha Orionis
- proper noun
- /ˈælfə ɔˈraɪənɪs/
- Specialized
- The brightness of Alpha Orionis can vary dramatically due to its size and age.
Examples
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Many amateur astronomers easily spot Alpha Orionis in the night sky during winter.
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Ancient cultures often used Alpha Orionis as a reference point for navigation.
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Look! Alpha Orionis is bright!
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Have you ever seen Alpha Orionis in the night sky?
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Many amateur astronomers easily spot Alpha Orionis in the night sky during winter.
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Ancient cultures often used Alpha Orionis as a reference point for navigation.
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The brightness of Alpha Orionis can vary dramatically due to its size and age.
Synonyms
A very large bright red star in the group of stars called Orion
Surface Forms
Morphology
alpha + Orionis
This is a conventional astronomical proper name formed from a Greek letter + a Latin genitive (Orionis = 'of Orion'), a morphological pattern unfamiliar to B1 learners and not compositional in the sense of everyday English. Knowing 'alpha' as 'first' and an unknown form 'Orionis' will not let a learner derive that it refers to a specific star (and details like brightness), so the meaning is not predictable from the constituents.
Etymology
Alpha Orionis comes from old star naming: Alpha means 'first' or 'main' and Orionis links the star to the hunter Orion, so the name points to this bright star in Orion, which astronomers also call 'Betelgeuse'.