天鵝座R

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觀測資料; 曆元 J2000
星座	天鵝座
星官
赤經	19h 36m 49.35633s
赤緯	+50° 11′ 59.7198″
視星等（V）	6.1 - 14.4
特性
光谱分类	S2.5,9e-S6,9e(Tc)
变星类型	米拉
天体测定
自行 (μ)	赤经：−3.158 mas/yr ; 赤纬：−5.755 mas/yr
视差 (π)	1.4835 ± 0.0963 mas
距离	2,200 ± 100 ly ; (670 ± 40 pc)
詳細資料
質量	0.85 M☉
表面重力 (log g)	−0.50
亮度	11,700 L☉
溫度	2,538 K
金属量 [Fe/H]	+0.50 dex
其他命名
	R Cyg、BD+49 3064、HD 185456、HIP 31822、SAO 31822、WDS J19368+5012
參考資料庫
SIMBAD	资料

天鵝座R是天鹅座中的米拉型的變星，距離奚仲三（天鵝座θ）不到4'。這是一顆位於漸近巨星支上的紅巨星，距離太陽約2,200光年遠。它是一顆光譜類型不同的S-型星，介於S2.5,9e 至 S6,9e(Tc)^[3]。

在這個質量範圍和演化階段的恆星是脈動不穩定的，顯示出它們輸出的亮度會變化^[7]。天鵝座R的最大星等為6.1等，最小星等為14.4等，週期為426.45天^[2]。這顆恆星的變異是由英國天文學家諾曼·羅伯特·普森（N. R. Pogson）在1852年發現的，它已經有一個多世紀以來記錄的亮度測量歷史^[7]。天鵝座R顯示出明顯的週期倍增，其中交替的最大值具有不同的亮度，因此脈動的真實週期可以被認為是從一個最大值到下一個最大值的兩倍^[8]。

双星和聚星星表列出了10等的BD+49 3065作為天鵝座R的伴星，相距91"，兩顆恆星與太陽的距離大致相同。華盛頓雙星目錄還列出了一顆15等恆星作為伴星，相距約14"^[9]。

參考資料

^ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天体在盖亚望远镜第二批数据发布的记录
^ ^2.0 ^2.1 ^2.2 Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N. General catalogue of variable stars: Version GCVS 5.1. Astronomy Reports. 2017, 61 (1): 80. Bibcode:2017ARep...61...80S. S2CID 125853869. doi:10.1134/S1063772917010085.
^ ^3.0 ^3.1 BSJ. R Cygni. AAVSO Website. American Association of Variable Star Observers. 4 January 2010 [21 January 2014]. （原始内容存档于2022-12-31）.
^ ^4.0 ^4.1 ^4.2 ^4.3 Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022). Vizier Online Data Catalog. 2022. Bibcode:2022yCat.1354....0A.
^ Guandalini, R; Francis, Charles. Infrared photometry and evolution of mass-losing AGB stars. III. Mass loss rates of MS and S stars. Astronomy and Astrophysics. 2010, 513: A4. Bibcode:2010A&A...513A...4G. S2CID 119193286. arXiv:1002.2458 . doi:10.1051/0004-6361/200911764.
^ R Cyg. SIMBAD. 斯特拉斯堡天文資料中心.
^ ^7.0 ^7.1 Kiss, L. L.; Szatmáry, K. Period-doubling events in the light curve of R Cygni: Evidence for chaotic behaviour. Astronomy and Astrophysics. August 2002, 390 (2): 585–596. Bibcode:2002A&A...390..585K. S2CID 17698877. arXiv:astro-ph/0205334 . doi:10.1051/0004-6361:20020744.
^ Kiss, L. L; Szatmáry, K. Period-doubling events in the light curve of R Cygni: Evidence for chaotic behaviour. Astronomy & Astrophysics. 2002, 390 (2): 585–596. Bibcode:2002A&A...390..585K. S2CID 17698877. arXiv:astro-ph/0205334 . doi:10.1051/0004-6361:20020744.
^ Mason, Brian D; Wycoff, Gary L; Hartkopf, William I; Douglass, Geoffrey G; Worley, Charles E. The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog. The Astronomical Journal. 2001, 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920 .

[GaiaDR2-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 Brown, A. G. A.; Vallenari, A.; Prusti, T.; de Bruijne, J. H. J.; et al. Gaia Data Release 2. Summary of the contents and survey properties. Astronomy & Astrophysics. 2018. Bibcode:2018A&A...616A...1G. arXiv:1804.09365 . doi:10.1051/0004-6361/201833051. VizieR中此天体在盖亚望远镜第二批数据发布的记录

[gcvs-2] 2.0 ^2.1 ^2.2 Samus', N. N; Kazarovets, E. V; Durlevich, O. V; Kireeva, N. N; Pastukhova, E. N. General catalogue of variable stars: Version GCVS 5.1. Astronomy Reports. 2017, 61 (1): 80. Bibcode:2017ARep...61...80S. S2CID 125853869. doi:10.1134/S1063772917010085.

[AAVSOR-3] 3.0 ^3.1 BSJ. R Cygni. AAVSO Website. American Association of Variable Star Observers. 4 January 2010 [21 January 2014]. （原始内容存档于2022-12-31）.

[starhorse2-4] 4.0 ^4.1 ^4.2 ^4.3 Anders, F.; Khalatyan, A.; Queiroz, A. B. A.; Chiappini, C.; Ardevol, J.; Casamiquela, L.; Figueras, F.; Jimenez-Arranz, O.; Jordi, C.; Monguio, M.; Romero-Gomez, M.; Altamirano, D.; Antoja, T.; Assaad, R.; Cantat-Gaudin, T.; Castro-Ginard, A.; Enke, H.; Girardi, L.; Guiglion, G.; Khan, S.; Luri, X.; Miglio, A.; Minchev, I.; Ramos, P.; Santiago, B. X.; Steinmetz, M. VizieR Online Data Catalog: StarHorse2, Gaia EDR3 photo-astrometric distances (Anders+, 2022). Vizier Online Data Catalog. 2022. Bibcode:2022yCat.1354....0A.

[guandalini-5] Guandalini, R; Francis, Charles. Infrared photometry and evolution of mass-losing AGB stars. III. Mass loss rates of MS and S stars. Astronomy and Astrophysics. 2010, 513: A4. Bibcode:2010A&A...513A...4G. S2CID 119193286. arXiv:1002.2458 . doi:10.1051/0004-6361/200911764.

[SIMBAD-6] R Cyg. SIMBAD. 斯特拉斯堡天文資料中心.

[Kiss2002-7] 7.0 ^7.1 Kiss, L. L.; Szatmáry, K. Period-doubling events in the light curve of R Cygni: Evidence for chaotic behaviour. Astronomy and Astrophysics. August 2002, 390 (2): 585–596. Bibcode:2002A&A...390..585K. S2CID 17698877. arXiv:astro-ph/0205334 . doi:10.1051/0004-6361:20020744.

[kiss-8] Kiss, L. L; Szatmáry, K. Period-doubling events in the light curve of R Cygni: Evidence for chaotic behaviour. Astronomy & Astrophysics. 2002, 390 (2): 585–596. Bibcode:2002A&A...390..585K. S2CID 17698877. arXiv:astro-ph/0205334 . doi:10.1051/0004-6361:20020744.

[wds-9] Mason, Brian D; Wycoff, Gary L; Hartkopf, William I; Douglass, Geoffrey G; Worley, Charles E. The 2001 US Naval Observatory Double Star CD-ROM. I. The Washington Double Star Catalog. The Astronomical Journal. 2001, 122 (6): 3466. Bibcode:2001AJ....122.3466M. doi:10.1086/323920 .

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天鵝座R

參考資料

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