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]
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Ursa Major |
| A | |
| Right ascension | 13h 40m 23.2324s[1] |
| Declination | +50° 31′ 09.8962″[1] |
| Apparent magnitude (V) | 6.32[2] |
| B | |
| Right ascension | 13h 40m 24.5190s[3] |
| Declination | +50° 30′ 57.5709″[3] |
| Apparent magnitude (V) | 10.51[4] |
| Characteristics | |
| Spectral type | F8 V[5] + K7[6] |
| U−B color index | −0.01[2] |
| B−V color index | +0.52[2] |
| Astrometry | |
| A | |
| Radial velocity (Rv) | −12.2±0.3[7] km/s |
| Proper motion (μ) | RA: −125.728±0.047[1] mas/yr Dec.: 58.567±0.046[1] mas/yr |
| Parallax (π) | 39.2353 ± 0.0354 mas[1] |
| Distance | 83.13 ± 0.08 ly (25.49 ± 0.02 pc) |
| Absolute magnitude (MV) | 4.30[8] |
| B | |
| Proper motion (μ) | RA: −131.130±0.044[3] mas/yr Dec.: 59.299±0.049[3] mas/yr |
| Parallax (π) | 39.3513 ± 0.0326 mas[3] |
| Distance | 82.88 ± 0.07 ly (25.41 ± 0.02 pc) |
| Details | |
| A | |
| Mass | 1.15[9] M☉ |
| Radius | 1.1[10] R☉ |
| Luminosity | 1.5[10] L☉ |
| Temperature | 6,149[11] K |
| Metallicity [Fe/H] | −0.18[11] dex |
| Rotational velocity (v sin i) | 10.2[12] km/s |
| Age | 2.06±22[12] Gyr |
| B | |
| Mass | 0.63[9] M☉ |
| Temperature | 4,130[13] K |
| Other designations | |
| A: BD+51°1859, GJ 521.2, HIP 66704, HR 5148, SAO 28836[15] | |
| B: BD+51°1859 B, HIP 66704 B, HR 5148 B, TYC 3469-1423-1, 2MASS J13402450+5030576[16] | |
| Database references | |
| SIMBAD | data |
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]