Rho Centauri
Binary star system in the constellation Centaurus
From Wikipedia, the free encyclopedia
Rho Centauri is a binary star[13] system in the southern constellation of Centaurus. Its name is a Bayer designation that is Latinized from ρ Centauri, and abbreviated Rho Cen or ρ Cen. This star is visible to the naked eye as a blue-white hued point of light with a combined apparent visual magnitude of +3.97.[1] The system is located approximately 276 light years from the Sun based on parallax, and is drifting further away with a radial velocity of around +15 km/s.[5] It is a proper motion member of the Lower Centaurus–Crux sub-group in the Scorpius–Centaurus OB association, the nearest such association of co-moving massive stars to the Sun.[3]
The primary component of this system is a B-type main-sequence star with a stellar classification of B3 V.[3] It is about 24[11] million years old with a high rate of spin, showing a projected rotational velocity of 147 km/s.[10] It has 5.4[7] times the mass of the Sun and 3.8[8] times the Sun's radius. The star is radiating 810[1] times the luminosity of the Sun from its photosphere at an effective temperature of 19,500 K.[9]
The secondary companion is 1.1 magnitudes fainter than the primary, with a projected separation of 5.68 AU along a position angle of 19.72°, as of 2013.[13] It revolves around the primary star in 3.6 years, on an ecccentric orbit.[6] The mass is estimated at 3.6 times that of the Sun, or 66% that of the primary.[7]