HD 134687

HD 134687
Location of HD 134687 (circled in red)
Observation data
Epoch J2000      Equinox ICRS
Constellation Lupus
Right ascension 15h 12m 49.58752s
Declination −44° 30′ 01.4904″
Apparent magnitude (V) 4.81
Characteristics
Evolutionary stage main sequence
Spectral type B3 IV/V
B−V color index −0.177±0.011
Astrometry
Radial velocity (Rv)+13.5±7.4 km/s
Proper motion (μ) RA: −21.669 mas/yr
Dec.: −21.895 mas/yr
Parallax (π)7.2373±0.2045 mas
Distance450 ± 10 ly
(138 ± 4 pc)
Absolute magnitude (MV)−1.11
Orbit
Period (P)0.901407 d
Eccentricity (e)≤ 0.03
Periastron epoch (T)0.366
Details
e Lup A
Mass6.0±0.1 M☉
Radius7.1 R☉
Luminosity (bolometric)997 L☉
Temperature17,100 K
Rotational velocity (v sin i)13 km/s
Age20.3±4.8 Myr
Other designations
e Lup, CD−44°9932, HD 134687, HIP 74449, HR 5651, SAO 225539
Database references
SIMBADdata

HD 134687 (e Lupi) is a binary star system in the southern constellation Lupus. It is visible to the naked eye with an apparent visual magnitude of 4.81. The distance to HD 134687 can be estimated from its annual parallax shift of 7.2 mas, yielding roughly 450 light years. It is a member of the ~11 million year old Upper Centaurus–Lupus subgroup of the Scorpius–Centaurus association, the closest OB association to the Sun.

This is a single-lined spectroscopic binary star system. The pair have a nearly circular orbit with an eccentricity of at or below 0.03 and a period of 0.901407 days (21.6338 h). The primary has an a sin i value of 2.735×105 km, which only gives a lower bound for the semimajor axis a since the orbital inclination i to the line of sight is unknown. The system is a source for X-ray emission.

The visible component has a stellar classification of B3 IV/V, matching a B-type star showing a spectrum with mixed traits of a main sequence and a subgiant star. It is 20 million years old with a projected rotational velocity of 13 km/s. The star has 6.0 times the mass of the Sun and 7.1 times the Sun's radius. It is radiating 997 times the Sun's luminosity from its photosphere at an effective temperature of 17,100 K.

References

  1. 1 2 3 Anderson, E.; Francis, Ch. (2012). "XHIP: An extended hipparcos compilation". Astronomy Letters. 38 (5): 331. arXiv:1108.4971. Bibcode:2012AstL...38..331A. doi:10.1134/S1063773712050015. XHIP record for this object at VizieR.
  2. 1 2 3 4 5 6 7 Vallenari, A.; et al. (Gaia collaboration) (2023). "Gaia Data Release 3. Summary of the content and survey properties". Astronomy and Astrophysics. 674: A1. arXiv:2208.00211. Bibcode:2023A&A...674A...1G. doi:10.1051/0004-6361/202243940. S2CID 244398875. Gaia DR3 record for this source at VizieR.
  3. 1 2 3 4 5 6 Hohle, M. M.; Neuhäuser, R.; Schutz, B. F. (April 2010), "Masses and luminosities of O- and B-type stars and red supergiants", Astronomische Nachrichten, 331 (4): 349, arXiv:1003.2335, Bibcode:2010AN....331..349H, doi:10.1002/asna.200911355, S2CID 111387483.
  4. 1 2 Houk, Nancy (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 2, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode:1978mcts.book.....H.
  5. ↑ de Bruijne, J. H. J.; Eilers, A.-C. (October 2012), "Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project", Astronomy & Astrophysics, 546: 14, arXiv:1208.3048, Bibcode:2012A&A...546A..61D, doi:10.1051/0004-6361/201219219, S2CID 59451347, A61.
  6. 1 2 Buscombe, W.; Kennedy, P. M. (August 1962), "Two B-Type Spectroscopic Binaries", Publications of the Astronomical Society of the Pacific, 74 (439): 323, Bibcode:1962PASP...74..323B, doi:10.1086/127818
  7. 1 2 Tetzlaff, N.; et al. (January 2011), "A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun", Monthly Notices of the Royal Astronomical Society, 410 (1): 190–200, arXiv:1007.4883, Bibcode:2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x, S2CID 118629873.
  8. 1 2 Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS)", Astronomy and Astrophysics, 367 (2) (Third ed.): 521–524, arXiv:astro-ph/0012289, Bibcode:2001A&A...367..521P, doi:10.1051/0004-6361:20000451, S2CID 425754.
  9. 1 2 Wolff, S. C.; Strom, S. E.; Dror, D.; Venn, K. (2007), "Rotational Velocities for B0-B3 Stars in Seven Young Clusters: Further Study of the Relationship between Rotation Speed and Density in Star-Forming Regions", The Astronomical Journal, 133 (3): 1092–1103, arXiv:astro-ph/0702133, Bibcode:2007AJ....133.1092W, doi:10.1086/511002, S2CID 119074863.
  10. ↑ "HD 134687". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2018-07-22.
  11. ↑ Chen, Christine H.; et al. (September 2012), "A Spitzer MIPS Study of 2.5–2.0 M☉ Stars in Scorpius–Centaurus", The Astrophysical Journal, 756 (2): 24, arXiv:1207.3415, Bibcode:2012ApJ...756..133C, doi:10.1088/0004-637X/756/2/133, S2CID 119278056, 133.
  12. ↑ Berghoefer, T. W.; Schmitt, J. H. M. M.; Cassinelli, J. P. (September 1996), "The ROSAT all-sky survey catalogue of optically bright OB-type stars", Astronomy and Astrophysics Supplement, 118 (3): 481–494, Bibcode:1996A&AS..118..481B, doi:10.1051/aas:1996213.