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Lambda Lupi 
Summary
Lambda Lupi, Latinized from λ Lupi, is a triple star[11] system in the southern constellation of Lupus. It is visible to the naked eye with a combined apparent visual magnitude of 4.04.[2] Based upon an annual parallax shift of just 4.20[1] mas as seen from Earth, it is located roughly 800 light years from the Sun. The system has a peculiar velocity of 27.4±4.9 km/s relative to its neighbors, making it a candidate runaway star system.[9] It is a member of the Upper Centaurus–Lupus sub-group in the Scorpius–Centaurus OB association.[12]
| Observation data Epoch J2000.0 Equinox J2000.0 (ICRS) | |
|---|---|
| Constellation | Lupus |
| Right ascension | 15h 08m 50.61639s[1] |
| Declination | −45° 16′ 47.4950″[1] |
| Apparent magnitude (V) | 4.04[2] (4.43 + 5.23)[3] |
| Characteristics | |
| Spectral type | B3 V[4] (B3 V + B3 V)[5] |
| U−B color index | −0.67[2] |
| B−V color index | −0.18[2] |
| Astrometry | |
| Radial velocity (Rv) | +9.80±1.78[6] km/s |
| Proper motion (μ) | RA: −15.88[1] mas/yr Dec.: −26.80[1] mas/yr |
| Parallax (π) | 4.20 ± 0.66 mas[1] |
| Distance | approx. 800 ly (approx. 240 pc) |
| Absolute magnitude (MV) | −2.75[7] |
| Orbit[8] | |
| Period (P) | 70.8±0.8 yr |
| Semi-major axis (a) | 0.2597±0.0021″ |
| Eccentricity (e) | 0.6283±0.0090 |
| Inclination (i) | 71.59±0.41° |
| Longitude of the node (Ω) | 26.64±0.61° |
| Periastron epoch (T) | 1997.907 ± 0.105 |
| Argument of periastron (ω) (secondary) | 299.9±1.1° |
| Details | |
| λ Lup A | |
| Mass | 8.14[8] M☉ |
| Rotational velocity (v sin i) | 135 km/s |
| Age | 28.1±4.1[9] Myr |
| λ Lup B | |
| Mass | 5.84 M☉ |
| Other designations | |
| Database references | |
| SIMBAD | data |
The two visible components of this system orbit each other over a period of 70.8 years with a large eccentricity of 0.63.[8] The primary component has a visual magnitude of 4.43, while the secondary is of magnitude 5.23.[3] Both are B-type main sequence stars with a stellar classification of B3 V.[5] One of the pair is itself a double-lined spectroscopic binary, making this a triple star system.[11]
References edit
- ^ a b c d e f van Leeuwen, F. (2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600.
- ^ a b c d Mermilliod, J.-C. (1986), "Compilation of Eggen's UBV data, transformed to UBV (unpublished)", Catalogue of Eggen's UBV Data, SIMBAD, Bibcode:1986EgUBV........0M.
- ^ a b Eggleton, P. P.; Tokovinin, A. A. (September 2008), "A catalogue of multiplicity among bright stellar systems", Monthly Notices of the Royal Astronomical Society, 389 (2): 869–879, arXiv:0806.2878, Bibcode:2008MNRAS.389..869E, doi:10.1111/j.1365-2966.2008.13596.x, S2CID 14878976.
- ^ 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.
- ^ a b Edwards, T. W. (April 1976), "MK classification for visual binary components", Astronomical Journal, 81: 245–249, Bibcode:1976AJ.....81..245E, doi:10.1086/111879. The system is listed in Table II as −44°9889.
- ^ 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.
- ^ 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, S2CID 119257644.
- ^ a b c Tokovinin, Andrei (2012), "Speckle Interferometry and Orbits of "Fast" Visual Binaries", The Astronomical Journal, 144 (2), 56, arXiv:1206.1882, Bibcode:2012AJ....144...56T, doi:10.1088/0004-6256/144/2/56, S2CID 118586009.
- ^ a b 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.
- ^ "* lam Lup". SIMBAD. Centre de données astronomiques de Strasbourg. Retrieved 2017-03-07.
{{cite web}}: CS1 maint: postscript (link) - ^ a b Nitschelm, C. (December 2004), "Discovery and confirmation of some double-lined spectroscopic binaries in the Sco-Cen Complex", in Hilditch, R. W.; Hensberge, H.; Pavlovski, K. (eds.), In Spectroscopically and Spatially Resolving the Components of the Close Binary Stars, Proceedings of the Workshop held 20-24 October 2003 in Dubrovnik, Croatia, ASP Conference Series, vol. 318, San Francisco: Astronomical Society of the Pacific, pp. 291–293, Bibcode:2004ASPC..318..291N.
- ^ Wolff, S. C.; et al. (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.
External links edit
- Kaler, James B. (June 20, 2014), "Lambda Lupi", Stars, University of Illinois, retrieved 2017-03-08.