天鵝座BI
天鵝座BI （BI Cyg」、IRC +40408、BD+36 4025）是在天鵝座的一顆紅超巨星。它是一顆不規則變星，最大亮度為星等8.4，最暗星等9.9。 它被認為是天鵝座OB1星協的成員[4]，距離太陽系大約2,600秒差距（8,500光年）。它位於另一個也是變星的紅超巨星天鵝座BC以南不到一度的地方。
| 觀測資料 曆元 J2000 | |
|---|---|
| 星座 | 天鵝座 |
| 星官 | |
| 赤經 | 20h 21m 21.8869s[1] |
| 赤緯 | 36° 55′ 55.729″[1] |
| 視星等（V） | 8.4 - 9.9[2] |
| 特性 | |
| 光譜分類 | M4 Iab[2] |
| 變星類型 | Lc[2] |
| 天體測定 | |
| 自行 (μ) | 赤經：−2.751[1] mas/yr 赤緯：−5.459[1] mas/yr |
| 視差 (π) | 0.3541 ± 0.0377[1] mas |
| 距離 | 2,579+232 −226[3] pc |
| 絕對星等 (MV) | −6.78[4] |
| 詳細資料 | |
| 質量 | 6.3[5] M☉ |
| 半徑 | 797[6] R☉ |
| 表面重力 (log g) | -0.35[5] |
| 亮度 | 64,000 - 67,000[7] L☉ |
| 溫度 | 3,550±170[7] K |
| 金屬量 [Fe/H] | +0.40[5] dex |
| 2016 (maximum) | |
| 半徑 | 908+12 −10[8] R☉ |
| 2015 (minimum) | |
| 半徑 | 852+12 −9[8] R☉ |
| Other designations | |
| 參考資料庫 | |
| SIMBAD | 資料 |
天鵝座BI是一顆慢不規則變星，被歸類為Lc型，一顆不規則的超巨星。 它的亮度極值在星等8.4和9.9等之間變化[2]。其光變曲線的頻率分析顯示沒有顯著的週期[10]。
天鵝座BI是已知最大的恆星之一，基於3,575K的有效溫度和226,000 L☉，其半徑大約是1,240 R☉[4]。最近的研究得出的亮度較低，低於 130,000 L☉，建議其初始量質為20 M☉，因此半徑值也較低[11][12][7]。
相關條件
編輯參考資料
編輯- ^ 1.0 1.1 1.2 1.3 1.4 Vallenari, A.; et al. Gaia Data Release 3. Summary of the content and survey properties. Astronomy & Astrophysics. 2022. arXiv:2208.00211
. doi:10.1051/0004-6361/202243940 . 已忽略未知參數|collaboration=(幫助) Gaia DR3 record for this source at VizieR. - ^ 2.0 2.1 2.2 2.3 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.
- ^ Bailer-Jones, C. A. L.; Rybizki, J.; Fouesneau, M.; Demleitner, M.; Andrae, R. Estimating Distances from Parallaxes. V. Geometric and Photogeometric Distances to 1.47 Billion Stars in Gaia Early Data Release 3. The Astronomical Journal. 2021, 161 (3): 147. Bibcode:2021AJ....161..147B. S2CID 228063812. arXiv:2012.05220 . doi:10.3847/1538-3881/abd806.
- ^ 4.0 4.1 4.2 Table 4 in Levesque, Emily M.; Massey, Philip; Olsen, K. A. G.; Plez, Bertrand; Josselin, Eric; Maeder, Andre; Meynet, Georges. The Effective Temperature Scale of Galactic Red Supergiants: Cool, but Not As Cool As We Thought. The Astrophysical Journal. August 2005, 628 (2): 973–985. Bibcode:2005ApJ...628..973L. S2CID 15109583. arXiv:astro-ph/0504337 . doi:10.1086/430901.
- ^ 5.0 5.1 5.2 Anders, F.; Khalatyan, A.; Chiappini, C.; Queiroz, A. B.; Santiago, B. X.; Jordi, C.; Girardi, L.; Brown, A. G. A.; Matijevič, G.; Monari, G.; Cantat-Gaudin, T.; Weiler, M.; Khan, S.; Miglio, A.; Carrillo, I.; Romero-Gómez, M.; Minchev, I.; De Jong, R. S.; Antoja, T.; Ramos, P.; Steinmetz, M.; Enke, H. Photo-astrometric distances, extinctions, and astrophysical parameters for Gaia DR2 stars brighter than G = 18. Astronomy and Astrophysics. 2019, 628: A94. Bibcode:2019A&A...628A..94A. S2CID 131780028. arXiv:1904.11302 . doi:10.1051/0004-6361/201935765.
- ^ Comerón, F.; Djupvik, A. A.; Schneider, N.; Pasquali, A. The historical record of massive star formation in Cygnus. Astronomy & Astrophysics. October 2020, 2009: A62. Bibcode:2020A&A...644A..62C. S2CID 221970180. arXiv:2009.12779 . doi:10.1051/0004-6361/202039188.
- ^ 7.0 7.1 7.2 Messineo, M.; Brown, A. G. A. A Catalog of Known Galactic K-M Stars of Class I Candidate Red Supergiants in Gaia DR2. The Astronomical Journal. 2019, 158 (1): 20. Bibcode:2019AJ....158...20M. S2CID 148571616. arXiv:1905.03744 . doi:10.3847/1538-3881/ab1cbd.
- ^ 8.0 8.1 Norris, Ryan P. Seeing Stars Like Never Before: A Long-term Interferometric Imaging Survey of Red Supergiants (PDF) (學位論文). Georgia State University. 2019 [2023-08-14]. （原始內容存檔 (PDF)於2022-01-24）.
- ^ OMC Archive. OMC Archive. The Astronomical Data Centre at CAB. [19 December 2021]. （原始內容存檔於2022-11-30）.
- ^ Kiss, L. L; Szabó, Gy. M; Bedding, T. R. Variability in red supergiant stars: Pulsations, long secondary periods and convection noise. Monthly Notices of the Royal Astronomical Society. 2006, 372 (4): 1721–1734. Bibcode:2006MNRAS.372.1721K. S2CID 5203133. arXiv:astro-ph/0608438 . doi:10.1111/j.1365-2966.2006.10973.x.
- ^ Nicolas Mauron; Eric Josselin. The mass-loss rates of red supergiants and the de Jager prescription. Astronomy and Astrophysics. 2010, 526: A156. Bibcode:2011A&A...526A.156M. S2CID 119276502. arXiv:1010.5369 . doi:10.1051/0004-6361/201013993.
- ^ Josselin, E.; Plez, B. Atmospheric dynamics and the mass loss process in red supergiant stars. Astronomy and Astrophysics. 2007, 469 (2): 671–680. Bibcode:2007A&A...469..671J. S2CID 17789027. arXiv:0705.0266 . doi:10.1051/0004-6361:20066353.
