Eta Capricorni

Eta Capricorni (η Cap, η Capricorni) is a binary star in the constellation Capricornus. It is approximately 167 light years from Earth.

The primary component, η Capricorni A, is a white A-type main sequence dwarf with an apparent magnitude of +4.82. Its companion, η Capricorni B, has an apparent magnitude of +6.5 and is located 0.34 arcseconds from the primary.

Sometimes, this star is called by the name Armus.

Chinese Name

In Chinese, 十二國 (Shíer Guó), meaning Twelve States, refers to an asterism which is represent twelve ancient states in the Spring and Autumn Period and the Warring States period, consisting of η Capricorni, φ Capricorni, ι Capricorni, 38 Capricorni, 35 Capricorni, 36 Capricorni, χ Capricorni, θ Capricorni, 30 Capricorni, 33 Capricorni, ζ Capricorni, 19 Capricorni, 26 Capricorni, 27 Capricorni, 20 Capricorni and 21 Capricorni. Consequently, η Capricorni itself is known as 周一 (Zhou yī, English: the First Star of Zhou), meaning that this star (together with 21 Capricorni and β Serpentis in Right Wall of Heavenly Market Enclosure (asterism)) represent Zhou (周) (possibly Chow, the dynasty in China).