Phi_Centauri
Phi Centauri
Star in the constellation Centaurus
Phi Centauri, Latinized from φ Centauri, is a blue-white hued star in the southern constellation Centaurus. It is visible to the naked eye with an apparent visual magnitude of +3.7.[2] The annual parallax shift is 6.21 mas[1] as measured from Earth, which yields a distance estimate of around 530 light years. It is moving further from the Sun with a radial velocity of +5 km/s.[5]
This is a B-type subgiant star with a stellar classification of B2 IV.[3] It has no known companions, but does show radial velocity variations and higher order pulsations in the spectrum.[9] The star is just 18[3] million years old with 8.5[3] times the mass of the Sun and has 4.2[6] times the Sun's radius. It is radiating around 4,000[7] times the Sun's luminosity from its photosphere at an effective temperature of about 21,638 K.[6]
This star is a proper motion member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[7]