15_Orionis
15 Orionis
Star system in the constellation Orion
15 Orionis is a suspected astrometric binary[9] star system in the equatorial constellation of Orion, near the border with Taurus. It is visible to the naked eye as a faint, yellow-white hued star with an apparent visual magnitude of 4.82.[2] The system is approximately 340 light years away from the Sun based on parallax. It is moving further from the Earth with a heliocentric radial velocity of +29 km/s,[4] having come to within 69 light-years some three million years ago.[5]
The primary component is an early F-type subgiant star with a stellar classification of F2 IV,[3] a star that has exhausted the hydrogen at its core and has begun to evolve into a giant. It has 3.42[6] times the mass of the Sun and 5.9[7] times the Sun's radius. The star still has a relatively high rotation rate, showing a projected rotational velocity of 60 km/s.[6] It is radiating 300 times the luminosity of the Sun from its expanding photosphere at an effective temperature of 7,161 K.[6]
It has one suspected companion, component B, at a separation of 0.3".[10]