盾牌座γ
盾牌座γ,名稱來自拉丁文的Gamma Scuti,是一顆單獨的[9],白色的恆星,位置在盾牌座的南部。它的視星等為4.67[2],表明這雖然是一顆暗星,但在足夠黑暗的場所依然可以肉眼看見。根據從地球上觀察到的10.21mas的周年視差[1],這顆恆星距離太陽約319光年。現時,它正以41km/s的速度向太陽系移動,這意味着在235萬年後,它將以 20 ly(5.519 pc)的距離掠過[10],可能有一段時間成為夜空中最亮的恆星:視星等 − 2.1等[11]。
觀測資料 曆元 J2000 | |
---|---|
星座 | 盾牌座 |
星官 | |
赤經 | 18h 29m 11.85388s[1] |
赤緯 | -14° 33′ 56.9319″[1] |
視星等(V) | 4.67[2] |
特性 | |
光譜分類 | A2:V[3] |
U−B 色指數 | +0.04[4] |
B−V 色指數 | +0.07[4] |
天體測定 | |
徑向速度 (Rv) | -41.00[5] km/s |
自行 (μ) | 赤經:+3.22[1] mas/yr 赤緯:−4.02[1] mas/yr |
視差 (π) | 10.21 ± 0.24[1] mas |
距離 | 319 ± 8 ly (98 ± 2 pc) |
絕對星等 (MV) | −0.28[2] |
詳細資料 | |
質量 | 2.91[6] M☉ |
半徑 | 4.1[7] R☉ |
表面重力 (log g) | 2.09[8] |
亮度 | 150[6] L☉ |
溫度 | 9,016[6] K |
自轉速度 (v sin i) | 222[6] km/s |
年齡 | 237[8] Myr |
其他命名 | |
參考資料庫 | |
SIMBAD | 資料 |
這是一顆A型主序星[3],恆星分類為A2V[3],年齡約2億3,700萬年[8]。它以222km/s的投影旋轉速度快速旋轉[6]。這使恆星形成略為扁平的形狀,具有顯著的赤道隆起,估計比極半徑大21%[12]。估計這顆恆星的質量是太陽的2.91倍[6],半徑是太陽的4.1倍[7]。在表面9,016K的有效溫度下,來自其光球的輻射是太陽光度的150倍[6]。
參考資料
編輯- ^ 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. S2CID 18759600. arXiv:0708.1752 . doi:10.1051/0004-6361:20078357. Vizier catalog entry (頁面存檔備份,存於互聯網檔案館)
- ^ 2.0 2.1 2.2 Anderson, E.; Francis, Ch. XHIP: An extended hipparcos compilation. Astronomy Letters. 2012, 38 (5): 331. Bibcode:2012AstL...38..331A. S2CID 119257644. arXiv:1108.4971 . doi:10.1134/S1063773712050015. Vizier catalog entry (頁面存檔備份,存於互聯網檔案館)
- ^ 3.0 3.1 3.2 Abt, Helmut A.; Morrell, Nidia I. The Relation between Rotational Velocities and Spectral Peculiarities among A-Type Stars. Astrophysical Journal Supplement. 1995, 99: 135. Bibcode:1995ApJS...99..135A. doi:10.1086/192182.
- ^ 4.0 4.1 Mallama, A. Sloan Magnitudes for the Brightest Stars. The Journal of the American Association of Variable Star Observers. 2014, 42 (2): 443. Bibcode:2014JAVSO..42..443M.Vizier catalog entry (頁面存檔備份,存於互聯網檔案館)
- ^ 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. S2CID 119231169. arXiv:1606.08053 . doi:10.1134/S1063773706110065.
- ^ 6.0 6.1 6.2 6.3 6.4 6.5 6.6 Zorec, J.; Royer, F. Rotational velocities of A-type stars. Astronomy & Astrophysics. 2012, 537: A120. Bibcode:2012A&A...537A.120Z. S2CID 55586789. arXiv:1201.2052 . doi:10.1051/0004-6361/201117691. Vizier catalog entry (頁面存檔備份,存於互聯網檔案館)
- ^ 7.0 7.1 Allende Prieto, C.; Lambert, D. L. Fundamental parameters of nearby stars from the comparison with evolutionary calculations: Masses, radii and effective temperatures. Astronomy and Astrophysics. 1999, 352: 555–562. Bibcode:1999A&A...352..555A. arXiv:astro-ph/9911002 . Vizier catalog entry (頁面存檔備份,存於互聯網檔案館)
- ^ 8.0 8.1 8.2 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. S2CID 33401607. arXiv:1501.03154 . doi:10.1088/0004-637X/804/2/146. Vizier catalog entry (頁面存檔備份,存於互聯網檔案館)
- ^ 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.
- ^ Bailer-Jones, C. A. L., Close encounters of the stellar kind, Astronomy & Astrophysics, March 2015, 575: 13, Bibcode:2015A&A...575A..35B, S2CID 59039482, arXiv:1412.3648 , doi:10.1051/0004-6361/201425221, A35.
- ^ Kaler, Jim. Gamma Scuti. [2017-04-21]. (原始內容存檔於2016-03-05).
- ^ van Belle, Gerard T., Interferometric observations of rapidly rotating stars, The Astronomy and Astrophysics Review, March 2012, 20 (1): 51, Bibcode:2012A&ARv..20...51V, S2CID 119273474, arXiv:1204.2572 , doi:10.1007/s00159-012-0051-2.