dǒu宿xiù,即人马座ττ Sgr拜耳命名法)或人马座40佛氏命名法),是位于黄道南天星座人马座的一颗恒星

斗宿五(τ Sagittarii)
斗宿五的位置(红圈)
观测资料
历元 J2000.0
星座 人马座
星官 斗宿
赤经 19h 06m 56.40897s[1]
赤纬 –27° 40′ 13.5189″[1]
视星等(V) +3.326[2]
特性
光谱分类K1 III[3]
U−B 色指数+1.185[2]
B−V 色指数+1.170[2]
天体测定
径向速度 (Rv)+45.4[4] km/s
自行 (μ) 赤经:–50.61[1] mas/yr
赤纬:-249.80[1] mas/yr
视差 (π)28.3195 ± 0.3134[5] mas
距离115 ± 1 ly
(35.3 ± 0.4 pc)
绝对星等 (MV)0.48[6]
详细资料 [7]
质量1.25 M
半径15.71 R
表面重力 (log g)2.15
亮度87.6 L
温度4,459 K
金属量 [Fe/H]–0.27 dex
自转速度 (v sin i)1.04[8] km/s
年龄7.91 Gyr
其他命名
Namalsadirah 2、Rabi al Sadira、人马座τ、τ Sgr、 Tau Sgr、40 Sagittarii、CPD−27°6617、FK5 1496、GC 26291、HD 177716、HIP 93864、HR 7234、PPM 269078、SAO 187683
参考数据库
SIMBAD资料

描述

编辑

这是星座中较亮的成员之一,视星等为+3.3[2]。根据视差测量结果[1],这颗恒星与地球的距离大约是122光年(37秒差距)。

这是一颗光谱类型K1的巨星,质量大约是1.25 M。恒星包层比太阳略冷,有效温度为4,590K,使恒星呈浅橙色。这颗恒星以干涉测量术测得的角直径,在校正周边昏暗后,为3.93 ± 0.04 mas[9],在其估计距离处,其物理半径约为太阳半径的16倍[10]

斗宿五疑似一颗双星,但是尚未能确认其伴星。它的金属含量较低(Fe与H的比值比太阳低54%),且相对太阳的本动速度(64km/s,是当地平均速度的四倍)较高,这表明该恒星是来自银河系不同地区的访客[11]

斗宿五是一颗红群聚的巨星,是一颗质量与太阳相似的恒星,它耗尽了核心的氢,穿过红巨星分支成为水平分支星,已在核心进行氦融合[12]

哇!讯号

编辑

斗宿五是距离1977年的哇!讯号起源处最近的恒星(传统星座轮廓上的一部分)[11]

名称和词源

编辑

参考资料

编辑
  1. ^ 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, S2CID 18759600, arXiv:0708.1752 , doi:10.1051/0004-6361:20078357 
  2. ^ 2.0 2.1 2.2 2.3 Celis S., L., Photoelectric photometry of late-type variable stars, Astronomy and Astrophysics Supplement Series, October 1975, 22: 9–17, Bibcode:1975A&AS...22....9C 
  3. ^ Gray, R. O.; et al, Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample, The Astronomical Journal, July 2006, 132 (1): 161–170, Bibcode:2006AJ....132..161G, S2CID 119476992, arXiv:astro-ph/0603770 , doi:10.1086/504637 
  4. ^ Wilson, R. E. General Catalogue of Stellar Radial Velocities. Carnegie Institute of Washington D.C. 1953. Bibcode:1953GCRV..C......0W. 
  5. ^ Brown, A. G. A.; et al. Gaia Early Data Release 3: Summary of the contents and survey properties. Astronomy & Astrophysics. 2021, 649: A1. Bibcode:2021A&A...649A...1G. S2CID 227254300. arXiv:2012.01533 . doi:10.1051/0004-6361/202039657 .  已忽略未知参数|collaboration= (帮助) (勘误: doi:10.1051/0004-6361/202039657e). Gaia EDR3 record for this source at VizieR.
  6. ^ Cardini, D., Mg II chromospheric radiative loss rates in cool active and quiet stars, Astronomy and Astrophysics, January 2005, 430: 303–311, Bibcode:2005A&A...430..303C, S2CID 12136256, arXiv:astro-ph/0409683 , doi:10.1051/0004-6361:20041440. 
  7. ^ Reffert, Sabine; et al. Precise radial velocities of giant stars. VII. Occurrence rate of giant extrasolar planets as a function of mass and metallicity. Astronomy & Astrophysics. 2015, 574: A116. Bibcode:2015A&A...574A.116R. S2CID 59334290. arXiv:1412.4634 . doi:10.1051/0004-6361/201322360. hdl:10722/215277. 
  8. ^ Hekker, S.; Meléndez, J. Precise radial velocities of giant stars. III. Spectroscopic stellar parameters. Astronomy and Astrophysics. 2007, 475 (3): 1003. Bibcode:2007A&A...475.1003H. S2CID 10436552. arXiv:0709.1145 . doi:10.1051/0004-6361:20078233. 
  9. ^ Richichi, A.; et al, CHARM2: An updated Catalog of High Angular Resolution Measurements, Astronomy and Astrophysics, February 2005, 431 (2): 773–777, Bibcode:2005A&A...431..773R, doi:10.1051/0004-6361:20042039  
  10. ^ Lang, Kenneth R., Astrophysical formulae, Astronomy and astrophysics library 1 3rd, Birkhäuser, 2006 [2022-09-05], ISBN 3-540-29692-1, (原始内容存档于2023-07-28) . The radius (R*) is given by:
     
  11. ^ 11.0 11.1 The world's biggest mysteries scientists still can't solve. 2014-09-02 [2022-10-29]. (原始内容存档于2015-11-08). 
  12. ^ Alves, David R. K-Band Calibration of the Red Clump Luminosity. The Astrophysical Journal. 2000, 539 (2): 732–741. Bibcode:2000ApJ...539..732A. S2CID 16673121. arXiv:astro-ph/0003329 . doi:10.1086/309278. 
  13. ^ Teapot. constellation-guide.com. [2017-05-13]. (原始内容存档于2020-07-26). 
  14. ^ 14.0 14.1 Template:Cite bok
  15. ^ Jack W. Rhoads - Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Jet Propulsion Laboratory, California Institute of Technology; November 15, 1971 (PDF). [2022-10-29]. (原始内容存档 (PDF)于2011-08-05). 
  16. ^ (中文) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育资讯网 2006 年 5 月 11 日页面存档备份,存于互联网档案馆