天淵增二
天淵增二（人馬座θ1）是黃道星座人馬座中一對很靠近的聯星系統[10]。它的視星等視肉眼可見的 +4.37等[2]。根據從地球測得年周視差6.29mas的數值[1]，它與太陽的距離是520光年。在這個距離上，由於星際塵埃的消光，它的星等減少了0.24等[11]。
 | |
| 觀測資料 曆元 J2000.0 | |
|---|---|
| 星座 | 人馬座 |
| 星官 | |
| 赤經 | 19h 59m 44.17834s[1] |
| 赤緯 | −35° 16′ 34.7049″[1] |
| 視星等（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] |
| 軌道[5] | |
| 繞行週期 (P) | 2.1051 d |
| 偏心率 (e) | 0.00 |
| 近心点 曆元 (T) | 2411140.645 JD |
| 近心點幅角 (ω) (secondary) | 0.00° |
| 半振幅 (K1) (primary) | 15.9 km/s |
| 詳細資料 | |
| θ1 Sgr A | |
| 質量 | 6.6±0.1[6] M☉ |
| 半徑 | 5.6[7] R☉ |
| 亮度 (bolometric) | 2,271[8] L☉ |
| 溫度 | 17,900[8] K |
| 自轉速度 (v sin i) | 73[3] km/s |
| 年齡 | 32.8±5.0[6] Myr |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 资料 |
它是只有單一光譜線的光譜聯星，有著軌道週期正好2.1天的圓形的軌道[5]。可見的主星A是B型次巨星，光譜類型是B3IVp[3]，年齡大約3,300萬，投影自轉速度為每秒73公里[3]。主星的質量是太陽的6.6倍[6]，半徑是太陽的5.6倍 [7]。來自有效溫度17,900K[8]的光球層輻射的量是太陽光度的2,271倍[8]。
參考資料
- ^ 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. 斯特拉斯堡天文資料中心. [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.
