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狐狸座SV

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SV Vulpeculae

狐狸座 SV
觀測資料
曆元 J2000
星座 狐狸座
星官
赤經 19h 51m 30.90640s[1]
赤緯 27° 27′ 36.8307″[1]
視星等(V) 6.72 - 7.79[2]
特性
光譜分類F7Iab-K0Iab[2]
U−B 色指數+0.868 - +1.659[3]
B−V 色指數+1.149 - +1.786[3]
變星類型δ Cep[2]
天體測定
徑向速度 (Rv)−2.00[4] km/s
自行 (μ) 赤經:−1.50[1] mas/yr
赤緯:−6.57[1] mas/yr
視差 (π)0.180 ± 0.81[1] mas
距離2,450[5] pc
絕對星等 (MV)−6.21[5]
詳細資料
質量14.6 - 15.8[6] M
半徑187.9 - 238.4[7] R
表面重力 (log g)0.50 - 1.60[8]
亮度19,800[9] L
溫度4,861 - 6,110[8] K
金屬量+0.05[8]
其他命名
SV Vul, HD 187921, HIP 97717, BD+27°3536
參考資料庫
SIMBAD資料

狐狸座SV是為在狐狸座造父變星。它是一顆次巨星,距離地球大約8,000光年。

狐狸座SV 這顆造父變星的視星等範圍在6.72至7.79,週期為45.0121天。光變曲線高度的不對稱,從極小上升到極大只是從極大到極小的三分之一[10]。週期並以每年214秒的速率衰減[9]

狐狸座SV是一顆黃色的次巨星,光度約是太陽的20,000倍,光譜類型從晚期的F型變化至早期的K型。它的脈動和溫度變化範圍會低於5,000度並超過6,000度[8],半徑是最大時為216.5 R,脹縮的範圍在188 R至238 R[7]

狐狸座SV 的質量現在大約是15 M,並且估計在主序列時大約為17 M。這段時期的變化和大氣豐度顯示,這顆恆星是第二次穿越不穩定帶。第一次穿越不穩定帶是從主序星迅速過渡到變成紅巨星時,第二次穿越是在氦核心燃燒時,恆星進入藍迴圈,變得更熱之後再回到紅巨星階段[9]

參考資料

  1. ^ 1.0 1.1 1.2 1.3 1.4 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可免費查閱. doi:10.1051/0004-6361:20078357. 
  2. ^ 2.0 2.1 2.2 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. Bibcode:2009yCat....102025S. 
  3. ^ 3.0 3.1 Berdnikov, L. N. VizieR Online Data Catalog: Photoelectric observations of Cepheids in UBV(RI)c (Berdnikov, 2008). VizieR On-line Data Catalog: II/285. Originally published in: 2008yCat.2285....0B. 2008, 2285. Bibcode:2008yCat.2285....0B. 
  4. ^ Gontcharov, G. A. Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system. Astronomy Letters. 2006, 32 (11): 759. Bibcode:2006AstL...32..759G. arXiv:1606.08053可免費查閱. doi:10.1134/S1063773706110065. 
  5. ^ 5.0 5.1 Groenewegen, M. A. T. Baade-Wesselink distances and the effect of metallicity in classical cepheids. Astronomy and Astrophysics. 2008, 488: 25. Bibcode:2008A&A...488...25G. arXiv:0807.1269可免費查閱. doi:10.1051/0004-6361:200809859. 
  6. ^ Caputo, F.; Bono, G.; Fiorentino, G.; Marconi, M.; Musella, I. Pulsation and Evolutionary Masses of Classical Cepheids. I. Milky Way Variables. The Astrophysical Journal. 2005, 629 (2): 1021. Bibcode:2005ApJ...629.1021C. arXiv:astro-ph/0505149可免費查閱. doi:10.1086/431641. 
  7. ^ 7.0 7.1 Imbert, M. Détermination des rayons de Céphéides. V. Vitesses radiales et dimensions de 22 Céphéides galactiques. Determination of the radii of Cepheids V. Radial velocities and dimensions of 22 galactic Cepheids. Astronomy and Astrophysics Supplement. 1999, 140: 79. Bibcode:1999A&AS..140...79I. doi:10.1051/aas:1999515. 
  8. ^ 8.0 8.1 8.2 8.3 Kovtyukh, V. V.; Andrievsky, S. M.; Belik, S. I.; Luck, R. E. Phase-dependent Variation of the Fundamental Parameters of Cepheids. II. Periods Longer than 10 Days. The Astronomical Journal. 2005, 129: 433. Bibcode:2005AJ....129..433K. doi:10.1086/426339. 
  9. ^ 9.0 9.1 9.2 Turner, D. G.; Berdnikov, L. N. On the crossing mode of the long-period Cepheid SV Vulpeculae. Astronomy and Astrophysics. 2004, 423: 335. Bibcode:2004A&A...423..335T. doi:10.1051/0004-6361:20040163. 
  10. ^ Schaltenbrand, R.; Tammann, G. A. The light curve parameters of photoelectrically observed galactic Cepheids. Astronomy and Astrophysics Supplement. 1971, 4: 265. Bibcode:1971A&AS....4..265S.