大犬座ι
  | |
| 觀測資料 曆元 J2000 | |
|---|---|
| 星座 | 大犬座 |
| 星官 | 天狼 （井宿） |
| 赤經 | 06h 56m 08.22413s[1] |
| 赤緯 | −17° 03′ 15.2675″[1] |
| 視星等（V） | 4.40[2] (4.36 - 4.40[3]) |
| 特性 | |
| 光譜分類 | B3Ib[4]，或B3Ib/II[5] |
| U−B 色指數 | −0.74[6] |
| B−V 色指數 | −0.07[6] |
| 變星類型 | 仙王座β型?[2] |
| 天體測定 | |
| 徑向速度 (Rv) | +41.20[7] km/s |
| 自行 (μ) | 赤經：−3.56 ± 0.17[1] mas/yr 赤緯：+2.42 ±0.20[1] mas/yr |
| 視差 (π) | 1.04 ± 0.20[1] mas |
| 距離 | approx. 3,100 ly (approx. 1,000 pc) |
| 絕對星等 (MV) | −5.51[8] |
| 詳細資料 | |
| 質量 | 12.5[9] M☉ |
| 半徑 | 25.9[8] R☉ |
| 表面重力 (log g) | 2.60[10] |
| 亮度 | 47,000[8] L☉ |
| 溫度 | 17,000[10] K |
| 金屬量 [Fe/H] | −0.17[11] dex |
| 自轉速度 (v sin i) | 27±4[10] km/s |
| 年齡 | 14.8[9] Myr |
| 其他命名 | |
| 參考資料庫 | |
| SIMBAD | 資料 |
天狼增五（Iota Canis Majoris）的拉丁化源自ι Canis Majoris，孤獨的[12]位在南天星座的大犬座，是一顆超巨星變星。它的視星等在+4.36和+4.40之間變化著[3]。根據視差的測量，這顆恆星與地球相距約3,100光年。它正以+41.2Km/s的徑向速度遠離而去[7]。
天狼增五是一顆大質量的藍白色B型超巨星，光譜類型為B3Ib[4]。它被歸類為仙王座β型變星[3]，但超巨星光譜類型和一個多月的期意味著它不再被認為是這種類型的[2]。這顆恆星的年齡為1,480萬，並正以27Km/s投影旋轉速度自轉[10]。它的質量是太陽的12.5倍[9]，半徑是太陽的25.9倍[8]。天狼增五的光度是太陽的47,000倍[8]，光球層的有效溫度是17,000K[10]。
這顆恆星在與星際物質的相互作用中顯示出弓形激波特徵，但這種星雲與恆星在銀河系中的運動不一致[13]。
參考資料
[編輯]- ^ 1.0 1.1 1.2 1.3 1.4 van Leeuwen, F., Validation of the new Hipparcos reduction, Astronomy and Astrophysics, November 2007, 474 (2): 653–664, Bibcode:2007A&A...474..653V, S2CID 18759600, arXiv:0708.1752
, doi:10.1051/0004-6361:20078357
- ^ 2.0 2.1 2.2 Stankov, Anamarija; Handler, Gerald. Catalog of Galactic β Cephei Stars. The Astrophysical Journal Supplement Series. 2005, 158 (2): 193–216. Bibcode:2005ApJS..158..193S. ISSN 0067-0049. S2CID 119526948. arXiv:astro-ph/0506495 . doi:10.1086/429408.
- ^ 3.0 3.1 3.2 Samus, N. N.; Durlevich, O. V.; et al. VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013). VizieR On-line Data Catalog: B/GCVS. Originally Published in: 2009yCat....102025S. 2009, 1: 02025. Bibcode:2009yCat....102025S.
- ^ 4.0 4.1 Prinja, R. K.; Massa, D. L. Signature of wide-spread clumping in B supergiant winds. Astronomy and Astrophysics. 2010, 521: L55. Bibcode:2010A&A...521L..55P. ISSN 0004-6361. S2CID 59151633. arXiv:1007.2744 . doi:10.1051/0004-6361/201015252.
- ^ Houk, Nancy; Smith-Moore, M. Michigan catalogue of two-dimensional spectral types for the HD stars 4. Ann Arbor: Dept. of Astronomy, University of Michigan. 1978. Bibcode:1988mcts.book.....H.
- ^ 6.0 6.1 Mermilliod, J.-C. Compilation of Eggen's UBV data, transformed to UBV (unpublished). Catalogue of Eggen's UBV Data. 1986. Bibcode:1986EgUBV........0M.
- ^ 7.0 7.1 Gontcharov, G. A. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system. Astronomy Letters. 2006, 32 (11): 759–771. Bibcode:2006AstL...32..759G. ISSN 1063-7737. S2CID 119231169. arXiv:1606.08053 . doi:10.1134/S1063773706110065.
- ^ 8.0 8.1 8.2 8.3 8.4 Balona, L. A.; Engelbrecht, C. A. Photometry and frequency analysis of line profile variables. Monthly Notices of the Royal Astronomical Society. 1985, 214 (4): 559. Bibcode:1985MNRAS.214..559B. doi:10.1093/mnras/214.4.559 .
- ^ 9.0 9.1 9.2 Tetzlaff, N.; Neuhäuser, R.; Hohle, M. M. A catalogue of young runaway Hipparcos stars within 3 kpc from the Sun. Monthly Notices of the Royal Astronomical Society. 2011, 410: 190–200. Bibcode:2011MNRAS.410..190T. S2CID 118629873. arXiv:1007.4883 . doi:10.1111/j.1365-2966.2010.17434.x.
- ^ 10.0 10.1 10.2 10.3 10.4 Lefever, K.; Puls, J.; Morel, T.; Aerts, C.; Decin, L.; Briquet, M. Spectroscopic determination of the fundamental parameters of 66 B-type stars in the field-of-view of the CoRoT satellite. Astronomy and Astrophysics. 2010, 515: A74. Bibcode:2010A&A...515A..74L. S2CID 54028925. arXiv:0910.2851 . doi:10.1051/0004-6361/200911956.
- ^ Gies, Douglas R.; Lambert, David L. Carbon, nitrogen, and oxygen abundances in early B-type stars. Astrophysical Journal. 1992, 387: 673. Bibcode:1992ApJ...387..673G. doi:10.1086/171116.
- ^ 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. S2CID 14878976. arXiv:0806.2878 . doi:10.1111/j.1365-2966.2008.13596.x.
- ^ Bodensteiner, J.; Baade, D.; Greiner, J.; Langer, N. Infrared nebulae around bright massive stars as indicators for binary interactions. Astronomy & Astrophysics. October 2018, 618: 13. Bibcode:2018A&A...618A.110B. S2CID 118972162. arXiv:1806.01294 . doi:10.1051/0004-6361/201832722. A110.
