Betelgeuse

n. (Astronomy) Betelgeux, Alpha Orionis, red bright star of the first magnitude near Orion

Betelgeuse (Alpha (α) Orionis) is a semiregular variable star located 427 light-years away. It is the second brightest star in the constellation Orion, and the ninth brightest star in the night sky. Although it has the Bayer designation "alpha", it is not as bright as Rigel (Beta Orionis). It is a vertex of the Winter Triangle asterism.
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Noun
1. the second brightest star in Orion
(synonym) Alpha Orionis
(hypernym) supergiant
(member-holonym) Orion, The Hunter

. (Alpha Orionis) A star in the constellation of Orion which is a red giant. It has a spectral classification of M2. It is a variable star that changes its brightness between apparent magnitudes +0.1 and +1.2, that is, about 8000 times the sun.