常陈四,即猎犬座βBeta Canum Venaticorum、β CVn、β Canum Venaticorum),是一颗猎犬座黄矮星,视星等4.26[2],是猎犬座第二亮星。视差值118.49毫弧秒[1],因此与地球距离为27.53光年(8.44秒差距)。

Beta Canum Venaticorum
Diagram showing star positions and boundaries of the Auriga constellation and its surroundings
常陈四在猎犬座位置(圆圈处)
观测资料
历元 J2000
星座 猎犬座
星官 太微垣 常陈
赤经 12h 33m 44.54482s[1]
赤纬 +41° 21′ 26.9248″[1]
视星等(V) 4.26[2]
特性
光谱分类G0 V[2]
U−B 色指数0.04[3]
B−V 色指数0.58[3]
天体测定
径向速度 (Rv)+6.9[4] km/s
自行 (μ) 赤经:–704.75[1] mas/yr
赤纬:+292.74[1] mas/yr
视差 (π)118.49 ± 0.20[1] mas
距离27.53 ± 0.05 ly
(8.44 ± 0.01 pc)
绝对星等 (MV)4.64[5]
详细资料
质量1.025 ± 0.050[6] M
半径1.123 ± 0.028[7] R
表面重力 (log g)4.60[8]
亮度1.151 ± 0.018[7] L
温度5,653 ± 72[7] K
金属量 [Fe/H]–0.21[8] dex
自转速度 (v sin i)2.9 ± 0.4[9] km/s
年龄5.3[10] to 7.1[5] Gyr
其他命名
Chara, Asterion, Beta CVn, 8 CVn, BD +42 2321, FK5 470, HD 109358, HIP 61317, HR 4785, SAO 44230.[2]
参考数据库
SIMBAD资料
ARICNS资料

常陈四和猎犬座最亮星常陈一共同代表猎犬座中偏南方的猎犬。它的西方固有名称 Chara 原本指“南方的狗”,不过现在专指常陈四,在希腊语(χαρά)中的意思则是“欢乐”[11]

在中国该星属于太微垣常陈星官,常陈的意思是“禁卫军”[12],“常陈四”即代表该恒星是常陈星官的第四颗恒星[13]

观测

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常陈四的视星等为4.26,是猎犬座第二亮星。它的光谱类型是G0 V,属于黄矮星,并且自1943年起它的光谱就是G0 V型的标准光谱[14]。它的光谱中有来自色球层的极弱一次电离钙离子(Ca II)发射线,该发射线是和其他光谱类似恒星比较时的重要参考(Ca II 发射线容易被量测到,并且可用来量测恒星色球层的活跃成度)[15]

常陈四被认为是金属量稍低的恒星[8],不过它的质量、年龄和演化阶段都显示它和太阳相似[16],因此它被认为是类太阳恒星。它的质量比太阳高3%[6]、半径比太阳大12%、以及光度比太阳高15%[7]

常陈四在各分量上的空间速度(U, V, W) = (–25, 0, +2) km/s[16]。过去有人认为该恒星是一颗光谱联星,但进一步的观测证实它似乎并不是[17]。此外,搜寻常陈四旁可能存在的棕矮星也失败了,至少以目前仪器精确度来看并没有这样的伴星[18]。一颗视星等6等的恒星猎犬座10距离常陈四1.43光年(0.44秒差距)[19]

外星生命存在可能性

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2006年美国天文学家玛格丽特·杜布尔将常陈四列为寻找外星生命的优先候选恒星[20]。因为该恒星性质与太阳接近,天文生物学家将它列入距离太阳10秒差距内最感兴趣恒星名单中[16]。不过直到2009年仍未发现在常陈四旁有行星存在[6]

参考资料

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  1. ^ 1.0 1.1 1.2 1.3 1.4 1.5 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, November 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752 , doi:10.1051/0004-6361:20078357. 
  2. ^ 2.0 2.1 2.2 2.3 bet CVn -- Spectroscopic binary. SIMBAD. Centre de Données astronomiques de Strasbourg. [2010-07-04]. (原始内容存档于2015-12-12). 
  3. ^ 3.0 3.1 Argue, A. N. UBV photometry of 550 F, G and K type stars. Monthly Notices of the Royal Astronomical Society. 1966, 133: 475–493. Bibcode:1966MNRAS.133..475A. 
  4. ^ Wilson, Ralph Elmer. General Catalogue of Stellar Radial Velocities. Washington: Carnegie Institution of Washington. 1953. Bibcode:1953QB901.W495...... 
  5. ^ 5.0 5.1 Holmberg, J.; Nordström, B.; Andersen, J., The Geneva-Copenhagen survey of the solar neighbourhood. III. Improved distances, ages, and kinematics, Astronomy and Astrophysics, July 2009, 501 (3): 941–947, Bibcode:2009A&A...501..941H, arXiv:0811.3982 , doi:10.1051/0004-6361/200811191. 
  6. ^ 6.0 6.1 6.2 van Belle, Gerard T.; von Braun, Kaspar. Directly Determined Linear Radii and Effective Temperatures of Exoplanet Host Stars. The Astrophysical Journal. April 2009, 694 (2): 1085–1098. Bibcode:2009ApJ...694.1085V. arXiv:0901.1206 . doi:10.1088/0004-637X/694/2/1085. 
  7. ^ 7.0 7.1 7.2 7.3 Boyajian, Tabetha S.; et al, Stellar Diameters and Temperatures. I. Main-sequence A, F, and G Stars, The Astrophysical Journal, February 2012, 746 (1): 101, Bibcode:2012ApJ...746..101B, arXiv:1112.3316 , doi:10.1088/0004-637X/746/1/101. . See Table 10.
  8. ^ 8.0 8.1 8.2 Luck, R. Earle; Heiter, Ulrike. Dwarfs in the Local Region. The Astronomical Journal. 2006, 131 (2): 3069–3092. Bibcode:2006AJ....131.3069L. doi:10.1086/504080. 
  9. ^ Herrero, E.; et al, Optimizing exoplanet transit searches around low-mass stars with inclination constraints, Astronomy & Astrophysics, January 2012, 537: A147, Bibcode:2012A&A...537A.147H, arXiv:1110.5840 , doi:10.1051/0004-6361/201117809. 
  10. ^ Barry, Don C.; Cromwell, Richard H.; Hege, E. Keith. Chromospheric activity and ages of solar-type stars. Astrophysical Journal, Part 1. 1987, 315: 264–272. Bibcode:1987ApJ...315..264B. doi:10.1086/165131. 
  11. ^ Kaler, Jim. Beta Canum Venaticorum. Stars. University of Illinois. [2006-12-06]. (原始内容存档于2007-02-20). 
  12. ^ (中文) 中国星座神话, written by 陈久金. Published by 台湾书房出版有限公司, 2005, ISBN 978-986-7332-25-7.
  13. ^ (中文) 香港太空馆 - 研究资源 - 亮星中英对照表 互联网档案馆存档,存档日期2009-09-29., Hong Kong Space Museum. Accessed on line November 23, 2010.
  14. ^ Garrison, R. F., Anchor Points for the MK System of Spectral Classification, Bulletin of the American Astronomical Society, December 1993, 25: 1319 [2012-02-04], Bibcode:1993AAS...183.1710G, (原始内容存档于2019-06-25). 
  15. ^ Herbig, G. H. Chromospheric H-alpha emission in F8-G3 dwarfs, and its connection with the T Tauri stars. Astrophysical Journal. 1985, 289 (1): 269–278. Bibcode:1985ApJ...289..269H. doi:10.1086/162887. 
  16. ^ 16.0 16.1 16.2 de Mello, G. P.; del Peloso, E. F.; Ghezzi, L. Astrobiologically Interesting Stars Within 10 Parsecs of the Sun. Astrobiology (abstract). 2006, 6 (2): 308–331. Bibcode:2006AsBio...6..308P. PMID 16689649. arXiv:astro-ph/0511180 . doi:10.1089/ast.2006.6.308. 
  17. ^ Morbey, C. L.; Griffin, R. F. On the reality of certain spectroscopic orbits. Astrophysical Journal, Part 1. 1987, 317: 343–352. Bibcode:1987ApJ...317..343M. doi:10.1086/165281. 
  18. ^ Carson, J. C.; et al. The Cornell High-Order Adaptive Optics Survey for Brown Dwarfs in Stellar Systems. I. Observations, Data Reduction, and Detection Analyses. The Astronomical Journal. 2006, 130 (3): 1212–1220. Bibcode:2005AJ....130.1212C. arXiv:astro-ph/0506287 . doi:10.1086/432604. 
  19. ^ Shaya, Ed J.; Olling, Rob P., Very Wide Binaries and Other Comoving Stellar Companions: A Bayesian Analysis of the Hipparcos Catalogue, The Astrophysical Journal Supplement, January 2011, 192 (1): 2, Bibcode:2011ApJS..192....2S, arXiv:1007.0425 , doi:10.1088/0067-0049/192/1/2. 
  20. ^ Stars searched for extraterrestrials. PhysOrg.com. 2006-02-19 [2008-05-04]. (原始内容存档于2008-04-30). 

外部链接

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