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]

盾牌座γ(γ Scuti)
盾牌座γ的位置(紅圈)
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
γ Sct、​BD−14° 5071、​FK5 696、​GC 25220、​HD 170296、​HIP 90595、​HR 6930、​SAO 161520、​GSC 05702-02882
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

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  2. ^ 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. ^ 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. ^ 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
  5. ^ 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. ^ 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. ^ 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. ^ 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
  9. ^ 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. 
  10. ^ 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. 
  11. ^ Kaler, Jim. Gamma Scuti. [2017-04-21]. (原始內容存檔於2016-03-05). 
  12. ^ 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.