HD 119124

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HD 119124
Observation data
Epoch J2000      Equinox
Constellation Ursa Major
HD 119124 A
Right ascension 13h 40m 23.2321s[1]
Declination +50° 31′ 09.894″[1]
Apparent magnitude (V) 6.32[2]
HD 119124 B
Right ascension 13h 40m 24.508s[3]
Declination +50° 30′ 57.61″[3]
Apparent magnitude (V) 10.51[4]
Spectral type F8 V[5] + K7[6]
U−B color index −0.01[2]
B−V color index +0.52[2]
Radial velocity (Rv)−12.2±0.3[7] km/s
Proper motion (μ) RA: −125.556[1] mas/yr
Dec.: +58.690[1] mas/yr
Parallax (π)39.48 ± 0.43[1] mas
Distance82.6 ± 0.9 ly
(25.3 ± 0.3 pc)
Absolute magnitude (MV)4.30[8]
HD 119124 A
Mass1.15[9] M
Radius1.1[10] R
Luminosity1.5[10] L
Temperature6,149[11] K
Metallicity [Fe/H]−0.18[11] dex
Rotational velocity (v sin i)10.2[12] km/s
Age206±22[12] Gyr
HD 119124 B
Mass0.63[9] M
Temperature4,130[13] K
Other designations
BD+51° 1859, GJ 521.2, HD 119124, HIP 66704, HR 5148, SAO 28836, ADS 8992, WDS J13404+5031[14]
Database references

HD 119124 is a wide binary star[15] 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 ideal viewing conditions. An annual parallax shift of 39.48[1] mas provides a distance estimate of 83 light years. The pair are candidate members of the Castor Moving Group,[16] 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.[15]

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.[17] 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.[18]


  1. ^ a b c d e f Gaia Collaboration; et al. (November 2016), "Gaia Data Release 1. Summary of the astrometric, photometric, and survey properties", Astronomy & Astrophysics, 595: 23, arXiv:1609.04172, Bibcode:2016A&A...595A...2G, doi:10.1051/0004-6361/201629512, A2.
  2. ^ a b c d Oja, T. (August 1991), "UBV photometry of stars whose positions are accurately known. VI", Astronomy and Astrophysics Supplement Series, 89 (2): 415–419, Bibcode:1991A&AS...89..415O.
  3. ^ a b Cutri, R. M.; Skrutskie, M. F.; van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T.; Fowler, J.; Gizis, J.; Howard, E.; Huchra, J.; Jarrett, T.; Kopan, E. L.; Kirkpatrick, J. D.; Light, R. M.; Marsh, K. A.; McCallon, H.; Schneider, S.; Stiening, R.; ... (June 2003), 2MASS All-Sky Catalog of Point Sources, Bibcode:2003yCat.2246....0C.
  4. ^ a b Mason, B. D.; et al. (December 2001), "The Washington Visual Double Star Catalog", The Astronomical Journal, 122 (6): 3466−3471, Bibcode:2001AJ....122.3466M, doi:10.1086/323920
  5. ^ a b Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: Spectroscopy of Stars Earlier than M0 within 40 parsecs: The Northern Sample I", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770, Bibcode:2006AJ....132..161G, doi:10.1086/504637.
  6. ^ Stephenson, C. B. (January 1986), "Dwarf K and M stars of small proper motion found in a large spectroscopic survey", Astronomical Journal, 91: 144−159, Bibcode:1986AJ.....91..144S, doi:10.1086/113994.
  7. ^ a b Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters, 32 (11): 759–771, arXiv:1606.08053, Bibcode:2006AstL...32..759G, doi:10.1134/S1063773706110065.
  8. ^ Holmberg, J.; et al. (July 2009), "The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics", Astronomy and Astrophysics, 501 (3): 941–947, arXiv:0811.3982, Bibcode:2009A&A...501..941H, doi:10.1051/0004-6361/200811191.
  9. ^ a b c Tokovinin, A.; Kiyaeva, O. (2015), "Eccentricity distribution of wide binaries", Monthly Notices of the Royal Astronomical Society, 456 (2): 2070, arXiv:1512.00278, Bibcode:2016MNRAS.456.2070T, doi:10.1093/mnras/stv2825.
  10. ^ a b c d e f Chen, C. H.; et al. (December 1, 2005), "A Spitzer Study of Dusty Disks around Nearby, Young Stars", The Astrophysical Journal, 634 (2): 1372–1384, Bibcode:2005ApJ...634.1372C, doi:10.1086/497124.
  11. ^ a b c Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics, 551: 4, arXiv:1301.5651, Bibcode:2013A&A...551L...8P, doi:10.1051/0004-6361/201220364, L8.
  12. ^ a b c Zuckerman, B.; et al. (November 2013), "Young Stars near Earth: The Octans-Near Association and Castor Moving Group", The Astrophysical Journal, 778 (1): 12, arXiv:1309.2318, Bibcode:2013ApJ...778....5Z, doi:10.1088/0004-637X/778/1/5, 5.
  13. ^ Morales, J. C.; et al. (2008), "The effect of activity on stellar temperatures and radii", Astronomy and Astrophysics, 478 (2): 507−512, arXiv:0711.3523, Bibcode:2008A&A...478..507M, doi:10.1051/0004-6361:20078324.
  14. ^ "HD 119124". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-01-18.
  15. ^ a b Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal, 147 (4): 14, arXiv:1401.6827, Bibcode:2014AJ....147...87T, doi:10.1088/0004-6256/147/4/87, 87.
  16. ^ Caballero, J. A. (May 2010), "Reaching the boundary between stellar kinematic groups and very wide binaries. II. α Librae + KU Librae: a common proper motion system in Castor separated by 1.0 pc", Astronomy and Astrophysics, 514: A98, arXiv:1001.5432, Bibcode:2010A&A...514A..98C, doi:10.1051/0004-6361/200913986.
  17. ^ Adelman, S. J.; et al. (December 2000), "On the Variability of F1-F9 Luminosity Class III-V Stars", Information Bulletin on Variable Stars, 5003: 1, Bibcode:2000IBVS.5003....1A.
  18. ^ Haakonsen, Christian Bernt; Rutledge, Robert E. (September 2009), "XID II: Statistical Cross-Association of ROSAT Bright Source Catalog X-ray Sources with 2MASS Point Source Catalog Near-Infrared Sources", The Astrophysical Journal Supplement, 184 (1): 138–151, arXiv:0910.3229, Bibcode:2009ApJS..184..138H, doi:10.1088/0067-0049/184/1/138.