HD 119124 is a wide binary star[17] system in the circumpolar constellation of Ursa Major. With an apparent visual magnitude of 6.3,[2] it lies below the normal brightness limit of stars that are visible with the naked eye under most viewing conditions. An annual parallax shift of 39.24[1] mas for the A component provides a distance estimate of 83 light years. The pair are candidate members of the Castor Moving Group,[18] which implies a relatively youthful age of around 200 million years.[12] HD 119124 is moving closer to the Sun with a radial velocity of −12 km/s.[7]
This system was first identified as a double star by Friedrich von Struve (1793−1864) and catalogued as the 1774th entry in his list. As of 2015, the magnitude 10.5 K-type companion star was located at an angular separation of 18.10 arc seconds along a position angle of 135° from the brighter primary.[4] They appear to be gravitationally bound with an estimated orbital period of around 7,000 years and a linear projected separation of 444.6 AU.[17]
The primary, component A, is a Sun-like star[10] with a stellar classification of F8 V,[5] indicating it is an F-type main-sequence star that is generating energy via hydrogen fusion at its core. It is slightly larger and more massive than the Sun[10][9] and appears mildly variable.[19] The star is radiating 1.5[10] times the Sun's luminosity from its photosphere at an effective temperature of 6,149 K.[11]
HD 119124 A displays a strong infrared excess at a wavelength of 70 μm, indicating an orbiting circumstellar disk of cold dust. The emission fits a model with a grain temperature of 40 K, indicating a minimum orbital radius of 60 AU from the host star. The estimated grain lifetimes are 84,000 years – much shorter than the star's lifespan. This suggests the grains are being replenished via collisions between some number of larger bodies totaling around 1−6 times the mass of the Moon.[10]
This system is a likely (80.4% chance) source of the strong X-ray emission coming from these coordinates.[20]
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