天渊增二
天渊增二（人马座θ1）是黄道星座人马座中一对很靠近的联星系统[10]。它的视星等视肉眼可见的 +4.37等[2]。根据从地球测得年周视差6.29mas的数值[1]，它与太阳的距离是520光年。在这个距离上，由于星际尘埃的消光，它的星等减少了0.24等[11]。
 | |
| 观测资料 历元 J2000.0 | |
|---|---|
| 星座 | 人马座 |
| 星官 | |
| 赤经 | 19h 59m 44.17834s[1] |
| 赤纬 | −35° 16′ 34.7049″[1] |
| 视星等（V） | 4.37[2] |
| 特性 | |
| 光谱分类 | B3 IVp[3] |
| U−B 色指数 | −0.67[2] |
| B−V 色指数 | −0.15[2] |
| 天体测定 | |
| 自行 (μ) | 赤经：+5.60[1] mas/yr 赤纬：−25.81[1] mas/yr |
| 视差 (π) | 6.29 ± 0.21[1] mas |
| 距离 | 520 ± 20 ly (159 ± 5 pc) |
| 绝对星等 (MV) | −1.63[4] |
| 轨道[5] | |
| 绕行周期 (P) | 2.1051 d |
| 偏心率 (e) | 0.00 |
| 近心点 历元 (T) | 2411140.645 JD |
| 近心点幅角 (ω) (secondary) | 0.00° |
| 半振幅 (K1) (primary) | 15.9 km/s |
| 详细资料 | |
| θ1 Sgr A | |
| 质量 | 6.6±0.1[6] M☉ |
| 半径 | 5.6[7] R☉ |
| 亮度 (bolometric) | 2,271[8] L☉ |
| 温度 | 17,900[8] K |
| 自转速度 (v sin i) | 73[3] km/s |
| 年龄 | 32.8±5.0[6] Myr |
| 其他命名 | |
| 参考数据库 | |
| SIMBAD | 资料 |
它是只有单一光谱线的光谱联星，有着轨道周期正好2.1天的圆形的轨道[5]。可见的主星A是B型次巨星，光谱类型是B3IVp[3]，年龄大约3,300万，投影自转速度为每秒73公里[3]。主星的质量是太阳的6.6倍[6]，半径是太阳的5.6倍 [7]。来自有效温度17,900K[8]的光球层辐射的量是太阳光度的2,271倍[8]。
参考资料
- ^ 1.0 1.1 1.2 1.3 1.4 1.5 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.
- ^ 2.0 2.1 2.2 2.3 Nicolet, B., Photoelectric photometric Catalogue of homogeneous measurements in the UBV System, Astronomy and Astrophysics Supplement Series, 1978, 34: 1–49, Bibcode:1978A&AS...34....1N.
- ^ 3.0 3.1 3.2 3.3 Levato, H., Rotational velocities and spectral types for a sample of binary systems, Astronomy and Astrophysics, 1975, 19: 91, Bibcode:1975A&AS...19...91L
- ^ Anderson, E.; Francis, Ch., XHIP: An extended hipparcos compilation, Astronomy Letters, 2012, 38 (5): 331, Bibcode:2012AstL...38..331A, arXiv:1108.4971 , doi:10.1134/S1063773712050015.
- ^ 5.0 5.1 Pourbaix, D.; et al, SB9: The ninth catalogue of spectroscopic binary orbits, Astronomy and Astrophysics, 2004, 424 (2): 727, Bibcode:2004A&A...424..727P, arXiv:astro-ph/0406573 , doi:10.1051/0004-6361:20041213.
- ^ 6.0 6.1 6.2 Tetzlaff, N.; et al, A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun, Monthly Notices of the Royal Astronomical Society, January 2011, 410 (1): 190–200, Bibcode:2011MNRAS.410..190T, arXiv:1007.4883 , doi:10.1111/j.1365-2966.2010.17434.x.
- ^ 7.0 7.1 Pasinetti Fracassini, L. E.; et al, Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS), Astronomy and Astrophysics Third, February 2001, 367: 521–524, Bibcode:2001A&A...367..521P, arXiv:astro-ph/0012289 , doi:10.1051/0004-6361:20000451.
- ^ 8.0 8.1 8.2 8.3 Hohle, M. M.; et al, Masses and luminosities of O- and B-type stars and red supergiants, Astronomische Nachrichten, 2010, 331 (4): 349, Bibcode:2010AN....331..349H, arXiv:1003.2335 , doi:10.1002/asna.200911355.
- ^ tet01 Sgr. SIMBAD. 斯特拉斯堡天文资料中心. [2017-07-07].
- ^ 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.
- ^ 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.
