半人馬座Xi1

关于拜耳命名法的其它恒星系统，请见“半人马座Xi2”。

半人马座Xi¹ （ξ¹ Cen, ξ¹ Centauri）是在南天人马座的一颗单独的^[10] 恒星。它的视星等为裸眼可见的+4.83等^[2]，年周视差14.79mas^[1]，距离太阳大约221光年。 在这样的距离上，恒星会因为中间的星际尘埃造成消光，而使视星等减弱0.1等^[11]。星系NGC 4945就在半人马座Xi¹西方17 弧秒 ^[12]。

半人马座 ξ¹

半人马座ξ1是图中最亮的恒星，就在星系NGC 4945的右边。
观测资料 历元 J2000.0
星座	半人马座
星官
赤经	13h 03m 33.30528s[1]
赤纬	−49° 31′ 38.1518″[1]
视星等（V）	+4.83[2]
特性
光谱分类	A0 V[3]
U−B 色指数	+0.014[2]
B−V 色指数	+0.030[2]
天体测定
径向速度 (Rv)	5000000000000000000♠0.00±3.70[4] km/s
自行 (μ)	赤经：−47.55[1] mas/yr 赤纬：−11.52[1] mas/yr
视差 (π)	14.79 ± 0.27[1] mas
距离	221 ± 4 ly (68 ± 1 pc)
详细资料 [5]
质量	2.39 M☉
半径	2.7[6] R☉
表面重力 (log g)	7000411000000000000♠4.11±0.14
亮度	43.2[7] L☉
温度	7004104620000000000♠10,462±356 K
自转速度 (v sin i)	185[8] km/s
年龄	125 Myr
其他命名
半人马座ξ1、CD−48° 7887、 HD 113314、HIP 63724、HR 4933、SAO 223870[9]。
参考数据库
SIMBAD	资料

这是一颗A型主序星，恒星分类为A0V^[3]。他的年龄大约1亿2500万岁^[5]，有相对高速的自转，投影旋转速度为185 km/s^[8]。估计它的质量是2.4太阳质量^[5]，半径是太阳半径的2.7倍^[6]。从外层大气的有效温度10,462K^[5]，它辐射的光度是太阳光度的43倍^[7]。

参考资料

1. van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, arXiv:0708.1752 , doi:10.1051/0004-6361:20078357.
2. Gutierrez-Moreno, Adelina; Moreno, Hugo, A photometric investigation of the Scorpio-Centaurus association, Astrophysical Journal Supplement, June 1968, 15: 459, Bibcode:1968ApJS...15..459G, doi:10.1086/190168.
3. Bauwens, E. K. J.; et al, Candidate Calibrators for the In-Orbit Spectrophotometric Calibration of the MIRI Medium Resolution Spectrograph Onboard the James Webb Space Telescope, Deustua, Susana; Oliveira, Cristina (编), The 2010 STScI Calibration Workshop (PDF), Space Telescope Science Institute, 2010 [2016-01-10].
4. de Bruijne, J. H. J.; Eilers, A.-C., Radial velocities for the HIPPARCOS-Gaia Hundred-Thousand-Proper-Motion project, Astronomy & Astrophysics, October 2012, 546: 14, Bibcode:2012A&A...546A..61D, arXiv:1208.3048 , doi:10.1051/0004-6361/201219219, A61.
5. David, Trevor J.; Hillenbrand, Lynne A., The Ages of Early-Type Stars: Strömgren Photometric Methods Calibrated, Validated, Tested, and Applied to Hosts and Prospective Hosts of Directly Imaged Exoplanets, The Astrophysical Journal, 2015, 804 (2): 146, Bibcode:2015ApJ...804..146D, arXiv:1501.03154 , doi:10.1088/0004-637X/804/2/146.
6. Pasinetti Fracassini, L. E.; et al, Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS), Astronomy and Astrophysics 3rd, February 2001, 367: 521–524, Bibcode:2001A&A...367..521P, arXiv:astro-ph/0012289 , doi:10.1051/0004-6361:20000451.
7. McDonald, I.; et al, Fundamental Parameters and Infrared Excesses of Hipparcos Stars, Monthly Notices of the Royal Astronomical Society, 2012, 427 (1): 343–57, Bibcode:2012MNRAS.427..343M, arXiv:1208.2037 , doi:10.1111/j.1365-2966.2012.21873.x.
8. Uesugi, Akira; Fukuda, Ichiro, Catalogue of rotational velocities of the stars, Contributions from the Institute of Astrophysics and Kwasan Observatory (University of Kyoto), 1970, Bibcode:1970crvs.book.....U.
9. ksi01 Cen -- Star, SIMBAD Astronomical Database (Centre de Données astronomiques de Strasbourg), [2017-01-09], （原始内容存档于2019-05-14）.
10. Eggleton, P. P.; Tokovinin, A. A., A catalogue of multiplicity among bright stellar systems, Monthly Notices of the Royal Astronomical Society, September 2008, 389 (2): 869–879, Bibcode:2008MNRAS.389..869E, arXiv:0806.2878 , doi:10.1111/j.1365-2966.2008.13596.x.
11. Gontcharov, G. A., Spatial distribution and kinematics of OB stars, Astronomy Letters, November 2012, 38 (11): 694−706, Bibcode:2012AstL...38..694G, arXiv:1606.09028 , doi:10.1134/S1063773712110035.
12. O'Meara, Stephen James, Deep-Sky Companions: The Caldwell Objects 2nd, Cambridge University Press: 392, 2016, ISBN 1316033538.