Alpha Capricorni

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Alpha Capricorni is an optical double star in the constellation Capricornus. The pair comprises α¹ Capricorni (magnitude 4.27) and α² Capricorni (magnitude 3.58), about 0.11 degrees apart in the sky, and both are visible to the naked eye. The Bayer designation is Alpha Capricorni, with the two stars called α¹ and α² Capricorni. They have traditional Arabic names: Algedi (also Algiedi or Al Giedi), from al-jady meaning “the billy goat” or “kid.” The name Giedi is sometimes linked to the whole constellation. They were once known as Prima Giedi and Secunda Giedi. In 2016, the IAU approved the name Algedi for α² Capricorni, now in the IAU Catalog of Star Names. In Chinese astronomy, Alpha Capricorni is 牛宿二, the Second Star of the Ox.