Astronomy:HD 119124

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Short description: Binary star in the constellation Ursa Major
HD 119124
Observation data
{{#ifeq:J2000|J2000.0 (ICRS)|Epoch J2000.0      Equinox J2000.0 (ICRS)| Epoch J2000      [[Astronomy:Equinox (celestial coordinates)|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[1] mas
Distance83.13 ± 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[3] mas
Distance82.88 ± 0.07 ly
(25.41 ± 0.02 pc)
Details
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
Age2.06±22[12] Gyr
B
Mass0.63[9] M☉
Temperature4,130[13] K
Other designations
STF 1774, HD 119124, ADS 8992, CCDM J13404+5031, WDS J13404+5031[14]
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
SIMBADdata

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 astronomical unit|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]

References

  1. ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  2. ↑ 2.0 2.1 2.2 2.3 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. ↑ 3.0 3.1 3.2 3.3 3.4 Brown, A. G. A. (August 2018). "Gaia Data Release 2: Summary of the contents and survey properties". Astronomy & Astrophysics 616: A1. doi:10.1051/0004-6361/201833051. Bibcode: 2018A&A...616A...1G.  Gaia DR2 record for this source at VizieR.
  4. ↑ 4.0 4.1 Mason, B. D. et al. (December 2001), "The Washington Visual Double Star Catalog", The Astronomical Journal 122 (6): 3466−3471, doi:10.1086/323920, Bibcode: 2001AJ....122.3466M 
  5. ↑ 5.0 5.1 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, doi:10.1086/504637, Bibcode: 2006AJ....132..161G. 
  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, doi:10.1086/113994, Bibcode: 1986AJ.....91..144S. 
  7. ↑ 7.0 7.1 Gontcharov, G. A. (November 2006), "Pulkovo Compilation of Radial Velocities for 35495 Hipparcos stars in a common system", Astronomy Letters 32 (11): 759–771, doi:10.1134/S1063773706110065, Bibcode: 2006AstL...32..759G. 
  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, doi:10.1051/0004-6361/200811191, Bibcode: 2009A&A...501..941H. 
  9. ↑ 9.0 9.1 9.2 Tokovinin, A.; Kiyaeva, O. (2015), "Eccentricity distribution of wide binaries", Monthly Notices of the Royal Astronomical Society 456 (2): 2070, doi:10.1093/mnras/stv2825, Bibcode: 2016MNRAS.456.2070T. 
  10. ↑ 10.0 10.1 10.2 10.3 10.4 10.5 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, doi:10.1086/497124, Bibcode: 2005ApJ...634.1372C. 
  11. ↑ 11.0 11.1 11.2 Pace, G. (March 2013), "Chromospheric activity as age indicator. An L-shaped chromospheric-activity versus age diagram", Astronomy & Astrophysics 551: 4, doi:10.1051/0004-6361/201220364, L8, Bibcode: 2013A&A...551L...8P. 
  12. ↑ 12.0 12.1 12.2 Zuckerman, B. et al. (November 2013), "Young Stars near Earth: The Octans-Near Association and Castor Moving Group", The Astrophysical Journal 778 (1): 12, doi:10.1088/0004-637X/778/1/5, 5, Bibcode: 2013ApJ...778....5Z. 
  13. ↑ Morales, J. C. et al. (2008), "The effect of activity on stellar temperatures and radii", Astronomy and Astrophysics 478 (2): 507−512, doi:10.1051/0004-6361:20078324, Bibcode: 2008A&A...478..507M. 
  14. ↑ "WDS J13404+5031AB". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=WDS+J13404%2B5031AB. 
  15. ↑ "HD 119124". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+119124. 
  16. ↑ "HD 119124B". SIMBAD. Centre de données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=HD+119124B. 
  17. ↑ 17.0 17.1 Tokovinin, Andrei (April 2014), "From Binaries to Multiples. II. Hierarchical Multiplicity of F and G Dwarfs", The Astronomical Journal 147 (4): 14, doi:10.1088/0004-6256/147/4/87, 87, Bibcode: 2014AJ....147...87T. 
  18. ↑ 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, doi:10.1051/0004-6361/200913986, Bibcode: 2010A&A...514A..98C. 
  19. ↑ 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. 
  20. ↑ 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, doi:10.1088/0067-0049/184/1/138, Bibcode: 2009ApJS..184..138H. 



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