Alpha Lupi
| Observation data Epoch J2000 Equinox J2000 |
|
|---|---|
| Constellation | Lupus |
| Right ascension | 14h 41m 55.7556s[1] |
| Declination | –47° 23′ 17.520″[1] |
| Apparent magnitude (V) | 2.30 |
| Characteristics | |
| Spectral type | B1.5 III[2] |
| U−B color index | –0.88[3] |
| B−V color index | –0.20[3] |
| Variable type | Beta Cephei |
| Astrometry | |
| Radial velocity (Rv) | +5.4 ± 0.6[4] km/s |
| Proper motion (μ) | RA: –21.15[1] mas/yr Dec.: –24.22[1] mas/yr |
| Parallax (π) | 5.95 ± 0.76[1] mas |
| Distance | approx. 550 ly (approx. 170 pc) |
| Absolute magnitude (MV) | -3.83 |
| Details | |
| Temperature | 21,820 ± 2,160[5] K |
| Metallicity | ![\begin{smallmatrix}\left[\frac{m}{H}\right]\ =\ 0.04\ \pm\ 0.10\end{smallmatrix}](/2012-wikipedia_en_all_nopic_01_2012/I/4a803dadc18b0562df4815fae1cc13ff.png) [6] |
| Rotational velocity (v sin i) | 16[4] km/s |
| Age | 1.6–2.0 × 107[4] years |
| Other designations | |
Alpha Lupi (α Lupi, α Lup) is the brightest star in the constellation Lupus.
In Chinese, 騎官 (Qí Guān), meaning Imperial Guards, refers to an asterism consisting of α Lupi, γ Lupi, δ Lupi, κ Centauri, β Lupi, λ Lupi, ε Lupi, μ Lup, π Lupi and ο Lupi .[8] Consequently, α Lupi itself is known as 騎官十 (Qí Guān shí, English: the Tenth Star of Imperial Guards.).[9]
R. H. Allen had opinion that this star was listed it in the Chinese asterism Yang Mun or Men（南門), meaning "the South Gate", in his work Star-Names and their Meanings.[10] But in Chinese astronomy, 南門 is located in Horn mansion and consisted by α and ε Centauri. Yang Mun was translated in Pinyin as 陽門, meaning "the Yang Gate", refers to the asterism in Neck mansion, containing the stars in Centaurus.[11] Allen also suggested that the Babylonian name for the star was "Kakkab Su-gub Gud-Elim" (Star Left Hand of the Horned Bull).[10]
Alpha Lupi is a giant star of spectral type B1.5. In 1956 it was identified as a Beta Cephei variable.[12] The variability period is 0.29585 days[6] (or just over 7 hours, 6 minutes). The magnitude varies by about 0.03, or about 3% of the total luminosity. A small star situated near Alpha Lupi may just be an optical companion.
This star is a member of the Scorpius-Centaurus Association, the nearest OB association to the Sun. This is a gravitationally unbound stellar association with an estimated age of 16–20 million years. The association is also the source of a bubble of hot gas that contains the Sun.[4]
References
- ^ a b c d e Perryman, M. A. C. et al; Lindegren; Kovalevsky; Hoeg; Bastian; Bernacca; Crézé; Donati et al. (April 1997). "The HIPPARCOS Catalogue". Astronomy & Astrophysics 323: L49–L52. Bibcode 1997A&A...323L..49P.
- ^ Hiltner, W. A.; Garrison, R. F.; Schild, R. E. (July 1969). "MK Spectral Types for Bright Southern OB Stars". Astrophysical Journal 157: 313–326. Bibcode 1969ApJ...157..313H. doi:10.1086/150069.
- ^ a b Johnson, H. L.; Mitchell; Iriarte; Wisniewski; et al. (1966). "UBVRIJKL photometry of the bright stars". Communications of the Lunar and Planetary Laboratory 4 (99): 99. Bibcode 1966CoLPL...4...99J.
- ^ 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.
- ^ Sokolov, N. A. (May 1995). "The determination of T_eff_ of B, A and F main sequence stars from the continuum between 3200 A and 3600 A". Astronomy and Astrophysics Supplement 110: 553–564. Bibcode 1995A&AS..110..553S.
- ^ a b 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.
- ^ "V* alf Lup -- Variable Star of beta Cep type". SIMBAD. Centre de Données astronomiques de Strasbourg. http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=V*+alf+Lup. Retrieved 2009-10-26.
- ^ (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.]
- ^ a b Allen, R. H. (1963). Star Names: Their Lore and Meaning (Reprint ed.). New York, NY: Dover Publications Inc.. p. 279. ISBN 0-486-21079-0.
- ^ Allen transliterated 南門 as Nan Mun in Centaurus.
Allen, R. H. (1963). Star Names: Their Lore and Meaning. p. 153. - ^ Pagel, B. E. J. (1956). "Results of a search for bright β Cephei variables in the southern sky". Monthly Notices of the Royal Astronomical Society 116: 10–24. Bibcode 1956MNRAS.116...10P.
See also
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