弧矢二
外观
弧矢二是颗蓝色的超巨星,位于大犬座,相当于大犬的尾巴 | |
观测资料 历元 J2000 | |
---|---|
星座 | 大犬座 |
星官 | |
赤经 | 07h 24m 05.70228s[1] |
赤纬 | –29° 18′ 11.1798″[1] |
视星等(V) | 2.450[2] |
特性 | |
光谱分类 | B5 Ia[3] |
U−B 色指数 | −0.708[2] |
B−V 色指数 | −0.087[2] |
变星类型 | α Cyg[4] |
天体测定 | |
径向速度 (Rv) | 41.1[5] km/s |
自行 (μ) | 赤经:−4.14[1] mas/yr 赤纬:5.81[1] mas/yr |
视差 (π) | 1.64 ± 0.40[1] mas |
距离 | approx. 2,000 ly (approx. 600 pc) |
绝对星等 (MV) | -7.0[6] |
详细资料 | |
质量 | 19.19 ± 1.15[7] M☉ |
半径 | 56.3[6] R☉ |
亮度 | 105,442[7] L☉ |
温度 | 15,000[3] K |
自转速度 (v sin i) | 50[8] km/s |
其他命名 | |
参考资料库 | |
SIMBAD | 资料 |
弧矢二(η Cma,η Canis Majoris)位于星座的大犬座。它的传统名称源自阿拉伯语عذرا al-‘aðrā,英文是Aludra。自1943年起,它的光谱被作为此类恒星光谱分类的参考标准之一[9]。
在阿拉伯,عذرا al-‘aðrā的意思是"处女",弧矢七(大犬座ε)、弧矢一(大犬座δ)和军市增五(大犬座ο2)在阿拉伯文中合称为Al ʽAdhārā(ألعذاري)[10]。
在中国属于井宿下的星官弧矢(Hú Shǐ),意思是弓和箭[11]。这个星官还包括弧矢一(大犬座δ)、弧矢三(HD 63032)、HD 65456(弧矢四)、弧矢五(船尾座ο)、船尾座κ(弧矢六)、弧矢七(大犬座ε)、大犬座κ(弧矢八)和弧矢九(船尾座π)[12]。
性质
[编辑]弧矢二尽管离地球有一段距离,但因为它的本质(绝对星等)非常明亮,是太阳的许多倍,所以看起来依然很亮。它是颗蓝白色的超巨星,光谱类型为B5Ia,光度是太阳的176,000倍,直径约是太阳的80倍[13]。Hohle和他的同事利用视差、消光和光谱分析,测出它的质量是太阳的19.19倍,亮度是太阳的105,442倍[7]。它的年龄还只是太阳的一部分,但已经在生命的最后阶段。它还在继续膨胀中,可能成为一颗红巨星,但也可能已经通过这一阶段。但无论是何种状况,在未来的数百万年它都将成为超新星。
弧矢二是一颗天鹅座α型变星,它的亮度以4.7天的周期,在+2.38至+2.48等之间变化[4][14]。
同名物
[编辑]美国海军有两艘巨爵级货船,USS Aludra (AF-55)和USS Aludra (AK-72),以这颗恒星命名。
参考资料
[编辑]- ^ 1.0 1.1 1.2 1.3 1.4 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.
- ^ 2.0 2.1 2.2 Alcaino, Gonzalo, The Globular Clusters NGC 2808 and NGC 1851, Astrophysical Journal, June 1969, 156: 853, Bibcode:1969ApJ...156..853A, doi:10.1086/150019
- ^ 3.0 3.1 Prinja, R. K.; Massa, D. L., Signature of wide-spread clumping in B supergiant winds, Astronomy and Astrophysics, October 2010, 521: L55, Bibcode:2010A&A...521L..55P, arXiv:1007.2744 , doi:10.1051/0004-6361/201015252
- ^ 4.0 4.1 Kazarovets, E. V.; Samus, N. N.; Durlevich, O. V.; Frolov, M. S.; Antipin, S. V.; Kireeva, N. N.; Pastukhova, E. N. The 74th Special Name-list of Variable Stars. Information Bulletin on Variable Stars. 1999, 4659: 1. Bibcode:1999IBVS.4659....1K.
- ^ Wielen, R.; et al, Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions, Veröff. Astron. Rechen-Inst. Heidelb (Astronomisches Rechen-Institut Heidelberg), 1999, 35 (35): 1, Bibcode:1999VeARI..35....1W
- ^ 6.0 6.1 Underhill, A. B.; et al, Effective temperatures, angular diameters, distances and linear radii for 160 O and B stars, Monthly Notices of the Royal Astronomical Society, November 1979, 189 (3): 601–605, Bibcode:1979MNRAS.189..601U, doi:10.1093/mnras/189.3.601
- ^ 7.0 7.1 7.2 Hohle, M. M.; Neuhäuser, R.; Schutz, B. F., Masses and luminosities of O- and B-type stars and red supergiants, Astronomische Nachrichten, April 2010, 331 (4): 349, Bibcode:2010AN....331..349H, arXiv:1003.2335 , doi:10.1002/asna.200911355
- ^ Abt, Helmut A.; Levato, Hugo; Grosso, Monica, Rotational Velocities of B Stars, The Astrophysical Journal, July 2002, 573 (1): 359–365, Bibcode:2002ApJ...573..359A, doi:10.1086/340590
- ^ 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)
- ^ Allen, R. H., Star Names: Their Lore and Meaning Reprint, New York, NY: Dover Publications Inc: 130, 1963 [2010-12-12], ISBN 0-486-21079-0, (原始内容存档于2024-04-05)
- ^ 弧矢 (Hú Shǐ) is westernized into Koo She. R.H. Allen had opinion that Koo She refers to the asterism including δ Velorum and ω Velorum. AEEA opinion is, δ Velorum is member of 天社 (Tiān Shè), meaning Celestial Earth God's Temple asterism and ω Velorum is not member of any asterisms. 天社 (Tiān Shè) is westernized into Tseen She and R.H.Allen used the term Tseen She for Chinese name of η Carinae. See Richard Hinckley Allen: Star Names — Their Lore and Meaning: Argo Navis and (中文) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育资讯网 2006 年 7 月 17 日 (页面存档备份,存于互联网档案馆).
- ^ (中文) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育资讯网 2006 年 7 月 17 日 (页面存档备份,存于互联网档案馆)
- ^ Jerzykiewicz, M.; Molenda-Zakowicz, J. Empirical Luminosities and Radii of Early-Type Stars after Hipparcos (PDF). Acta Astronomica. 2000, 50: 369–80 [2016-01-16]. Bibcode:2000AcA....50..369J. (原始内容存档 (PDF)于2020-07-14).
- ^ Watson, Christopher. Eta Canis Majoris. AAVSO Website. American Association of Variable Star Observers. 3 May 2013 [5 February 2014]. (原始内容存档于2014-02-22).