Alpha1 Capricorni
{{DISPLAYTITLE:Alpha1 Capricorni}} Alpha1 Capricorni, Latinized from α1 Capricorni, is a distant, binary star system dominated by a highly luminous star in the constellation of Capricornus, north of the ecliptic. It has the traditional star names Prima Giedi () and Algiedi Prima (). The system is separated from the brighter Alpha2 Capricorni by 0.11° of the sky, a gap resolvable with the naked eye, similar to Mizar and Alcor. Both are not to be confused with much fainter 3 Capricorni nor somewhat fainter Nu Capricorni which are 3 to 6 times the angular distance apart than separate the two Alpha stars, respectively. The primary star is a yellow hued supergiant star with a stellar classification of G3 Ib. It has an apparent magnitude of +4.3; bright enough to make it visible to the naked eye. The star is located at a distance of approximately 870 light years from the solar system based on parallax measurements, but is drifting closer with a radial velocity of −25 km/s. The star is past first dredge-up and has already evolved through the Cepheid instability strip; it may be about to do so a second time. It has 5.3 times the mass and 36 times the