南十字座θ1

南十字座θ1(θ1Cru、θ1 Crucis) 是在南十字座的一對光譜聯星。它們的視星等是肉眼可見的+4.30m[2]。使用視差測量[1]得到與太陽的距離大約是235光年

南十字座θ1
觀測資料
曆元 J2000.0 (ICRS)
星座 南十字座θ
星官
赤經 12h 03m 01.50130s[1]
赤緯 −63° 18′ 46.5406″[1]
視星等(V) 4.30[2]
特性
光譜分類A3(m)A8-A8[3]
U−B 色指數+0.03[2]
B−V 色指數+0.28[2]
天體測定
徑向速度 (Rv)−2.4[4] km/s
自行 (μ) 赤經:−152.35[1] mas/yr
赤緯:+7.00[1] mas/yr
視差 (π)13.88 ± 0.15[1] mas
距離235 ± 3 ly
(72.0 ± 0.8 pc)
絕對星等 (MV)+1.29[5]
軌道[6]
繞行週期 (P)24.4828 d
偏心率 (e)0.61
近心點 曆元 (T)2419453.3470 JD
近心點幅角 (ω)
(secondary)
358.9°
半振幅 (K1)
(primary)
46.1 km/s
半振幅 (K2)
(secondary)
56.1 km/s
詳細資料
質量1.57[7] M
表面重力 (log g)3.76[7]
亮度81[8] L
溫度7341±250[7] K
年齡1.1[7] Gyr
其他命名
θ1 Cru, CPD−62° 2543, HD 104671, HIP 58758, HR 4599, SAO 251705.[9]
參考資料庫
SIMBAD資料

這一對的軌道互相接近的週期是24.5天,離心率0.61[6]。主星的光譜是Am星,是化學性質異常A型恆星,顯示有某些元素的吸收線異常變化[10]。它的恆星光譜是A3(m)A8-A8[3],質量是太陽的157%[7],它的外層大氣表面有效溫度是7341K[7],輻射出的光度是太陽的81倍[8]。異常的是檢測到的X射線輻射來自這顆A型星的整個輻射層,但也有可能來自於軌道上的同伴[11]

參考資料

  1. ^ 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. ^ 2.0 2.1 2.2 2.3 Mermilliod, J.-C., Compilation of Eggen's UBV data, transformed to UBV (unpublished), SIMBAD, 1986, Bibcode:1986EgUBV........0M. 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. ^ 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. 
  4. ^ Wilson, Ralph Elmer, General Catalogue of Stellar Radial Velocities, Washington: Carnegie Institution of Washington, 1953, Bibcode:1953GCRV..C......0W. 
  5. ^ 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. ^ 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. ^ 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. ^ 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. 
  9. ^ tet01 Cru. SIMBAD. 斯特拉斯堡天文資料中心. [2016-10-06]. 
  10. ^ 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. 
  11. ^ 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.