Beta Lupi
 Location of β Lupus (circled) |
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| Observation data Epoch J2000 Equinox J2000 |
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|---|---|
| Constellation | Lupus |
| Right ascension | 14h 58m 31.92536s[1] |
| Declination | -43° 08′ 02.2699″[1] |
| Apparent magnitude (V) | 2.68[2] |
| Characteristics | |
| Spectral type | B2 III[3] |
| U−B color index | –0.902[4] |
| B−V color index | –0.226[4] |
| Variable type | β Cep[5] |
| Astrometry | |
| Radial velocity (Rv) | +0.1 ± 1.0[3] km/s |
| Proper motion (μ) | RA: –35.78[1] mas/yr Dec.: –39.83[1] mas/yr |
| Parallax (π) | 8.52 ± 0.18[1] mas |
| Distance | 383 ± 8 ly (117 ± 2 pc) |
| Absolute magnitude (MV) | –3.3[6] |
| Details | |
| Mass | 8.8 ± 0.2[7] M☉ |
| Radius | 6.6[8] R☉ |
| Luminosity | 10,000[6] L☉ |
| Surface gravity (log g) | 3.76[6] |
| Temperature | 24,090[9] K |
| Metallicity [Fe/H] | −0.35 ± 0.11[5] dex |
| Rotational velocity (v sin i) | 92[3] km/s |
| Age | 24.6 ± 2.7[7] Myr |
| Other designations | |
Beta Lupi (β Lupi, β Lup) is a star in the southern constellation of Lupus. It has an apparent visual magnitude of 2.7,[2] making it readily visible to the naked eye. Based upon parallax measurements, this star is located at a distance of about 383 light-years (117 parsecs) from Earth.[2]
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[edit] Properties
The stellar classification of B2 III indicates this is a giant star.[3] The effective temperature of the star's outer envelope is 24,090 K,[9] giving it the blue-white hue of a B-type star.[11] With an age of around 25 million years,[7] it is near the end of its hydrogen phase, where hydrogen is fused into the element helium, and transferring into a red supergiant star. At about 8.8[7] solar masses, it may have enough mass to end its life as a Type II supernova, but there is the possibility of Beta Lupi becoming a white dwarf.[12]
This is a multi-period Beta Cephei variable with a dominant oscillation period of 0.232 days.[5] It is a proper motion member of the Upper-Centaurus Lupus sub-group in the Scorpius-Centaurus OB association, the nearest such co-moving association of massive stars to the Sun.[6] Beta Lupi has a high proper motion of more than 50 mas per year, suggesting a significant transverse velocity.[13]
It lies close to the supernova remnant SN 1006.[citation needed]
[edit] In culture
In Chinese, 騎官 (Qí Guān), meaning Imperial Guards, refers to an asterism consisting of β Lupi, γ Lupi, δ Lupi, κ Centauri, λ Lupi, ε Lupi, μ Lup, π Lupi, ο Lupi and α Lupi.[14] Consequently, β Lupi itself is known as 騎官四 (Qí Guān sì, English: the Fourth Star of Imperial Guards.)[15]. From this Chinese name, the name Ke Kwan was appeared.[16]
[edit] See also
[edit] References
- ^ a b c d e van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics 474 (2): 653–664, Bibcode 2007A&A...474..653V, doi:10.1051/0004-6361:20078357
- ^ a b c Wielen, R. et al. (1999), Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions, Astronomisches Rechen-Institut Heidelberg, Bibcode 1999VeARI..35....1W
- ^ a b c d Jilinski, E. et al. (March 2006), "Radial velocity measurements of B stars in the Scorpius-Centaurus association", Astronomy and Astrophysics 448 (3): 1001–1006, arXiv:astro-ph/0601643, Bibcode 2006A&A...448.1001J, doi:10.1051/0004-6361:20041614
- ^ a b 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
- ^ a b c Daszyńska-Daszkiewicz, J.; Niemczura, E. (April 2005), "Metallicity of mono- and multiperiodic β Cephei stars", Astronomy and Astrophysics 433 (3): 1031–1035, arXiv:astro-ph/0410442, Bibcode 2005A&A...433.1031D, doi:10.1051/0004-6361:20040397
- ^ a b c d de Geus, P. T.; de Zeeuw; Lub, J. (June 1989), "Physical parameters of stars in the Scorpio-Centaurus OB association", Astronomy and Astrophysics 216 (1-2): 44–61, Bibcode 1989A&A...216...44D
- ^ a b c d Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. (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, Bibcode 2011MNRAS.410..190T, doi:10.1111/j.1365-2966.2010.17434.x
- ^ Underhill, A. B. et al. (November 1979), "Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars", Monthly Notices of the Royal Astronomical Society 189: 601–605, Bibcode 1979MNRAS.189..601U
- ^ a b Zorec, J. et al. (July 2009), "Fundamental parameters of B supergiants from the BCD system. I. Calibration of the (λ_1, D) parameters into Teff", Astronomy and Astrophysics 501 (1): 297–320, Bibcode 2009A&A...501..297Z, doi:10.1051/0004-6361/200811147
- ^ "bet Lup -- Variable Star", SIMBAD (Centre de Données astronomiques de Strasbourg), http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Beta+Lupi, retrieved 2012-01-16
- ^ "The Colour of Stars", Australia Telescope, Outreach and Education (Commonwealth Scientific and Industrial Research Organisation), December 21, 2004, http://outreach.atnf.csiro.au/education/senior/astrophysics/photometry_colour.html, retrieved 2012-01-16
- ^ Kaler, James B. (2007), "Beta Lupi", Stars (University of Illinois), http://www.astro.illinois.edu/~jkaler/sow/betalup.html, retrieved 2009-07-03
- ^ Jiménez-Esteban, F. M.; Caballero, J. A.; Solano, E. (January 2011), "Identification of blue high proper motion objects in the Tycho-2 and 2MASS catalogues using Virtual Observatory tools", Astronomy and Astrophysics 525: A29, Bibcode 2011A&A...525A..29J, doi:10.1051/0004-6361/201015223
- ^ (Chinese) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ^ (Chinese) 香港太空館 - 研究資源 - 亮星中英對照表, Hong Kong Space Museum. Accessed on line November 23, 2010.]
- ^ Richard Hinckley Allen: Star Names — Their Lore and Meaning: Lupus
[edit] External links
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