Eta Capricorni

Eta Capricorni (η Cap, η Capricorni) is a binary star in the constellation Capricornus. It also has the traditional star name Arm. It is approximately 158 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.