Magnitude 4.27 Apparent magnitude (V) 4.27 | ||
Similar Gamma Capricorni, Beta Capricorni, Delta Capricorni, Alpha Capricorni, Omega Capricorni | ||
Alpha1 Capricorni (α1 Cap, α1 Capricorni) is a double star in the southern constellation of Capricornus. It also has the traditional star name Prima Giedi or Algiedi Prima, and shares the name Algedi (from الجدي - al-jadii, meaning the goat) with α² Capricorni. It is approximately 690 light years from Earth.
α1 Capricorni has three faint companions within one arc-minute. The brightest of these is 10th magnitude and on this basis it has often been considered as a double star. The separation of the stars is increasing rapidly due to the high proper motion of the primary star. The Hipparcos satellite also detected a new very close companion, 0.6" away and four magnitudes fainter.
The primary star is a yellow G3 supergiant with an apparent magnitude of +4.3. This star has 5.3 times the mass of the Sun and is radiating around 1,047 times the Sun's luminosity.
In popular culture
The name Giedi Prime is used for a fictional planet in Frank Herbert's 1965 science fiction novel Dune. This Giedi Prime is a planet of the star 36 Ophiuchi B, and is the home world of the villainous House Harkonnen.