From Wikipedia, the free encyclopedia
Lambda Librae
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Libra
Right ascension 15h 53m 20.05463s [1]
Declination −20° 10′ 01.4177″ [1]
Apparent magnitude (V) 5.03 [2]
Characteristics
Spectral type B3 V [3]
U−B color index −0.584 [2]
B−V color index −0.023 [2]
Variable type Rotating ellipsoidal [4]
Astrometry
Radial velocity (Rv)−2.0±0.5 [5] km/s
Proper motion (μ) RA: −9.81 [1]  mas/ yr
Dec.: −26.85 [1]  mas/ yr
Parallax (π)10.54 ± 0.91  mas [1]
Distance310 ± 30  ly
(95 ± 8  pc)
Absolute magnitude (MV)0.56 [6]
Orbit [7]
Period (P)14.4829±0.0004 d
Eccentricity (e)0.27±0.09
Periastron epoch (T)2435172.380 ± 0.664 JD
Argument of periastron (ω)
(secondary)
217±17°
Semi-amplitude (K1)
(primary)
28.5±3.3 km/s
Details
Mass5.01±0.26 [8]  M
Radius3.9 [9]  R
Luminosity743 [8]  L
Surface gravity (log g)4.75  cgs
Temperature18,700 [8]  K
Metallicity [Fe/H]−0.27  dex
Rotational velocity (v sin i)155 [10] km/s
Age282 [6]  Myr
Other designations
λ Lib, 45 Lib, BD−19°4249, FK5 1415, HD 142096, HIP 77811, HR 5902, SAO 183895. [11]
Database references
SIMBAD data

λ Librae (Latinised as Lambda Librae) is the Bayer designation for a binary star system in the zodiac constellation of Libra. It can be faintly seen with the naked eye, having an apparent visual magnitude of 5.03. [2] With an annual parallax shift of 10.54  mas, [1] it is roughly 310  light years from the Sun. At that distance, the visual magnitude of this system is diminished by an extinction factor of 0.22 due to interstellar dust. [6] It is 0.1 degree north of the ecliptic.

This is a single-lined spectroscopic binary star system with an orbital period of 14.48 days and an eccentricity of 0.27. [7] The visible component is a B-type main sequence star with a stellar classification of B3 V. [3] It is a helium-weak chemically peculiar star [12] and a rotating ellipsoidal variable. [4] The star has an estimated 3.9 [9] times the radius of the Sun and five times the Sun's mass. [8] This is a candidate Vega-like star, meaning that it shows an infrared excess characteristic of a circumstellar debris disk. [13] The system is a source of X-ray emission. [14]

References

  1. ^ 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.
  2. ^ a b c d Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode: 1968ApJS...15..459G, doi: 10.1086/190168.
  3. ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H.
  4. ^ a b Hoffleit, Dorrit (1996), "A Catalogue of Correlations Between Eclipsing Binaries and Other Categories of Double Stars", The Journal of the American Association of Variable Star Observers, 24 (2): 105–116, Bibcode: 1996JAVSO..24..105H.
  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. ^ a b c Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv: 1606.09028, Bibcode: 2012AstL...38..694G, doi: 10.1134/S1063773712110035, S2CID  119108982.
  7. ^ a b Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv: astro-ph/0406573, Bibcode: 2004A&A...424..727P, doi: 10.1051/0004-6361:20041213, S2CID  119387088.
  8. ^ a b c d 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.
  9. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, arXiv: astro-ph/0012289, Bibcode: 2001A&A...367..521P, doi: 10.1051/0004-6361:20000451, S2CID  425754.
  10. ^ Abt, Helmut A.; et al. (2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode: 2002ApJ...573..359A, doi: 10.1086/340590.
  11. ^ "lam Lib -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-01-30.
  12. ^ Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics, 498 (3): 961–966, Bibcode: 2009A&A...498..961R, doi: 10.1051/0004-6361/200810788.
  13. ^ Saffe, C.; Gómez, M.; Pintado, O.; González, E. (October 2008), "Spectroscopic metallicities of Vega-like stars", Astronomy and Astrophysics, 490 (1): 297–305, arXiv: 0805.3936, Bibcode: 2008A&A...490..297S, doi: 10.1051/0004-6361:200810260, S2CID  15059920.
  14. ^ 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.
From Wikipedia, the free encyclopedia
Lambda Librae
Observation data
Epoch J2000.0       Equinox J2000.0 ( ICRS)
Constellation Libra
Right ascension 15h 53m 20.05463s [1]
Declination −20° 10′ 01.4177″ [1]
Apparent magnitude (V) 5.03 [2]
Characteristics
Spectral type B3 V [3]
U−B color index −0.584 [2]
B−V color index −0.023 [2]
Variable type Rotating ellipsoidal [4]
Astrometry
Radial velocity (Rv)−2.0±0.5 [5] km/s
Proper motion (μ) RA: −9.81 [1]  mas/ yr
Dec.: −26.85 [1]  mas/ yr
Parallax (π)10.54 ± 0.91  mas [1]
Distance310 ± 30  ly
(95 ± 8  pc)
Absolute magnitude (MV)0.56 [6]
Orbit [7]
Period (P)14.4829±0.0004 d
Eccentricity (e)0.27±0.09
Periastron epoch (T)2435172.380 ± 0.664 JD
Argument of periastron (ω)
(secondary)
217±17°
Semi-amplitude (K1)
(primary)
28.5±3.3 km/s
Details
Mass5.01±0.26 [8]  M
Radius3.9 [9]  R
Luminosity743 [8]  L
Surface gravity (log g)4.75  cgs
Temperature18,700 [8]  K
Metallicity [Fe/H]−0.27  dex
Rotational velocity (v sin i)155 [10] km/s
Age282 [6]  Myr
Other designations
λ Lib, 45 Lib, BD−19°4249, FK5 1415, HD 142096, HIP 77811, HR 5902, SAO 183895. [11]
Database references
SIMBAD data

λ Librae (Latinised as Lambda Librae) is the Bayer designation for a binary star system in the zodiac constellation of Libra. It can be faintly seen with the naked eye, having an apparent visual magnitude of 5.03. [2] With an annual parallax shift of 10.54  mas, [1] it is roughly 310  light years from the Sun. At that distance, the visual magnitude of this system is diminished by an extinction factor of 0.22 due to interstellar dust. [6] It is 0.1 degree north of the ecliptic.

This is a single-lined spectroscopic binary star system with an orbital period of 14.48 days and an eccentricity of 0.27. [7] The visible component is a B-type main sequence star with a stellar classification of B3 V. [3] It is a helium-weak chemically peculiar star [12] and a rotating ellipsoidal variable. [4] The star has an estimated 3.9 [9] times the radius of the Sun and five times the Sun's mass. [8] This is a candidate Vega-like star, meaning that it shows an infrared excess characteristic of a circumstellar debris disk. [13] The system is a source of X-ray emission. [14]

References

  1. ^ 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.
  2. ^ a b c d Gutierrez-Moreno, Adelina; Moreno, Hugo (June 1968), "A photometric investigation of the Scorpio-Centaurus association", Astrophysical Journal Supplement, 15: 459, Bibcode: 1968ApJS...15..459G, doi: 10.1086/190168.
  3. ^ a b Houk, Nancy; Smith-Moore, M. (1978), Michigan catalogue of two-dimensional spectral types for the HD stars, vol. 4, Ann Arbor: Dept. of Astronomy, University of Michigan, Bibcode: 1988mcts.book.....H.
  4. ^ a b Hoffleit, Dorrit (1996), "A Catalogue of Correlations Between Eclipsing Binaries and Other Categories of Double Stars", The Journal of the American Association of Variable Star Observers, 24 (2): 105–116, Bibcode: 1996JAVSO..24..105H.
  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. ^ a b c Gontcharov, G. A. (November 2012), "Spatial distribution and kinematics of OB stars", Astronomy Letters, 38 (11): 694–706, arXiv: 1606.09028, Bibcode: 2012AstL...38..694G, doi: 10.1134/S1063773712110035, S2CID  119108982.
  7. ^ a b Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al. (2004), "SB9: The ninth catalogue of spectroscopic binary orbits", Astronomy & Astrophysics, 424 (2): 727–732, arXiv: astro-ph/0406573, Bibcode: 2004A&A...424..727P, doi: 10.1051/0004-6361:20041213, S2CID  119387088.
  8. ^ a b c d 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.
  9. ^ a b Pasinetti Fracassini, L. E.; et al. (February 2001), "Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) – Third edition – Comments and statistics", Astronomy and Astrophysics, 367 (2): 521–524, arXiv: astro-ph/0012289, Bibcode: 2001A&A...367..521P, doi: 10.1051/0004-6361:20000451, S2CID  425754.
  10. ^ Abt, Helmut A.; et al. (2002), "Rotational Velocities of B Stars", The Astrophysical Journal, 573 (1): 359–365, Bibcode: 2002ApJ...573..359A, doi: 10.1086/340590.
  11. ^ "lam Lib -- Spectroscopic binary", SIMBAD Astronomical Database, Centre de Données astronomiques de Strasbourg, retrieved 2017-01-30.
  12. ^ Renson, P.; Manfroid, J. (May 2009), "Catalogue of Ap, HgMn and Am stars", Astronomy and Astrophysics, 498 (3): 961–966, Bibcode: 2009A&A...498..961R, doi: 10.1051/0004-6361/200810788.
  13. ^ Saffe, C.; Gómez, M.; Pintado, O.; González, E. (October 2008), "Spectroscopic metallicities of Vega-like stars", Astronomy and Astrophysics, 490 (1): 297–305, arXiv: 0805.3936, Bibcode: 2008A&A...490..297S, doi: 10.1051/0004-6361:200810260, S2CID  15059920.
  14. ^ 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.

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