Alpha Orionis (Betelgeuse)

α Orionis
Alpha Orionis has perhaps the most famous star name in the heavens, Betelgeuse, which is a distortion of the Arabic ‘Jad al-Jauza’, the hand of the Central One.

     There is some confusion about just how ‘Betelgeuse’ is pronounced. Some declare that the first syllable must rhyme with 'metal'. Others adamantly proclaim that it should sound like 'beetle'.
     The last syllable -- it is also argued by some -- should sound just like 'juice'. Not a bit of it, say others, who opt for a zed (or zee) sound. The truth is, nobody knows, and you can jolly well pronounce it any way you like!

The star is a red supergiant, the brightest variable star in the heavens. With an estimated size of a thousand Solar radii, if placed in the position of our Sun, the star would displace Mercury, Venus, Earth and Mars. Only ten million years old, Betelgeuse's destiny will be that of a supernova many millions of years hence.

As a semiregular variable, it goes from a brightness of 0.2 (nearly as bright as Rigel) to 1.3 (nearly as bright as Aldebaran, alpha Taurus, to the northwest). The AASVO gives a period of 2335 days (=6 yrs 142 days), but as a semiregular, it has multiple unpredictable periods.


In binoculars, if you place Betelgeuse just below the centre of your field of vision then you will see two fairly bright stars in the same area, one to the northeast and one to the southwest: binoculars. They are both close binaries:
      52 Orionis is a white giant, a binary (Struve 795) with an identical companion: 6.0, 6.0; 222º, 1.2".
      mu Orionis is a multiple system (BU1056), with the second component a very faint 14 magnitude; AB: 4.3, 6.3; 21º, 0.4".

Continue with your discovery of Orion by clicking on any of the other orange-coloured stars or deep sky objects.

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