Rho Capricorni
Rho Capricorni is a binary star system in the constellation Capricornus. Its name is a Bayer designation that is Latinized from ρ Capricorni, and abbreviated Rho Cap or ρ Cap. Sometimes, this star is called by the name Bos, meaning the cow in Latin. In Chinese, 牛宿, meaning Ox , refers to an asterism consisting of β Capricorni, α2 Capricorni, ξ2 Capricorni, π Capricorni, ο Capricorni and ρ Capricorni. Consequently, the Chinese name for ρ Capricorni itself is 牛宿六
This system is visible to the naked eye with a combined apparent visual magnitude of +4.78. The pair orbit each other with a period of 278 years and an eccentricity of 0.91. Based upon an annual parallax shift of as seen from the Earth, the system is located about distant from the Sun. It is a thin disk population star system that made its closest approach to the Sun about 1.6 million years ago when it came within. Based upon its motion through space, this system may be a member of the Ursa Major moving group of stars.
The primary member, component A, is a yellow-white hued, F-type subgiant with an apparent magnitude of 4.97 and a stellar classification of F2 IV. This star has 1.5 times the mass of the Sun and 1.3 times the Sun's radius. It is radiating 9 times as much luminosity of the Sun from its outer atmosphere at an effective temperature of 6,911 K. The companion, component B, has a visual magnitude of 6.88. The mass ratio is 0.539, meaning the secondary is only 53.9% as massive as the primary.