南十字座θ1
南十字座θ1（θ1Cru、θ1 Crucis） 是在南十字座的一对光谱联星。它们的视星等是肉眼可见的+4.30m[2]。使用视差测量[1]得到与太阳的距离大约是235光年。
| 观测资料 历元 J2000.0 (ICRS) | |
|---|---|
| 星座 | 南十字座θ |
| 星官 | |
| 赤经 | 12h 03m 01.50130s[1] |
| 赤纬 | −63° 18′ 46.5406″[1] |
| 视星等（V） | 4.30[2] |
| 特性 | |
| 光谱分类 | A3(m)A8-A8[3] |
| U−B 色指数 | +0.03[2] |
| B−V 色指数 | +0.28[2] |
| 天体测定 | |
| 径向速度 (Rv) | −2.4[4] km/s |
| 自行 (μ) | 赤经：−152.35[1] mas/yr 赤纬：+7.00[1] mas/yr |
| 视差 (π) | 13.88 ± 0.15[1] mas |
| 距离 | 235 ± 3 ly (72.0 ± 0.8 pc) |
| 绝对星等 (MV) | +1.29[5] |
| 轨道[6] | |
| 绕行周期 (P) | 24.4828 d |
| 偏心率 (e) | 0.61 |
| 近心点 历元 (T) | 2419453.3470 JD |
| 近心点幅角 (ω) (secondary) | 358.9° |
| 半振幅 (K1) (primary) | 46.1 km/s |
| 半振幅 (K2) (secondary) | 56.1 km/s |
| 详细资料 | |
| 质量 | 1.57[7] M☉ |
| 表面重力 (log g) | 3.76[7] |
| 亮度 | 81[8] L☉ |
| 温度 | 7341±250[7] K |
| 年龄 | 1.1[7] Gyr |
| 其他命名 | |
| 参考资料库 | |
| SIMBAD | 资料 |
这一对的轨道互相接近的周期是24.5天，离心率0.61[6]。主星的光谱是Am星，是化学性质异常的A型恒星，显示有某些元素的吸收线异常变化[10]。它的恒星光谱是A3(m)A8-A8[3]，质量是太阳的157%[7]，它的外层大气表面有效温度是7341K[7]，辐射出的光度是太阳的81倍[8]。异常的是检测到的X射线辐射来自这颗A型星的整个辐射层，但也有可能来自于轨道上的同伴[11]。
参考资料
编辑- ^ 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- ^ 2.0 2.1 2.2 2.3 Mermilliod, J.-C., Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, 1986, Bibcode:1986EgUBV........0M.
- ^ 3.0 3.1 Houk, N.; Cowley, A. P., University of Michigan Catalogue of two-dimensional spectral types for the HD stars 1, 1975, Bibcode:1975mcts.book.....H.
- ^ Wilson, Ralph Elmer, General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, 1953, Bibcode:1953GCRV..C......0W.
- ^ Eggen, Olin J., The Age Range of Hyades Stars, The Astronomical Journal, July 1998, 116 (1): 284–292, Bibcode:1998AJ....116..284E, doi:10.1086/300413.
- ^ 6.0 6.1 Pourbaix, D.; Tokovinin, A. A.; Batten, A. H.; Fekel, F. C.; Hartkopf, W. I.; et al, SB9: The ninth catalogue of spectroscopic binary orbits, Astronomy & Astrophysics, 2004, 424 (2): 727, Bibcode:2004A&A...424..727P, arXiv:astro-ph/0406573 , doi:10.1051/0004-6361:20041213.
- ^ 7.0 7.1 7.2 7.3 7.4 7.5 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.
- ^ 8.0 8.1 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.
- ^ tet01 Cru. SIMBAD. 斯特拉斯堡天文资料中心. [2016-10-06].
- ^ Renson, P.; Manfroid, J., Catalogue of Ap, HgMn and Am stars, Astronomy and Astrophysics, May 2009, 498 (3): 961–966, Bibcode:2009A&A...498..961R, doi:10.1051/0004-6361/200810788.
- ^ Schröder, C.; Schmitt, J. H. M. M., X-ray emission from A-type stars, Astronomy and Astrophysics, November 2007, 475 (2): 677–684, Bibcode:2007A&A...475..677S, doi:10.1051/0004-6361:20077429.
