史蒂文森2-18

**史蒂芬森2-18**
	; 2MASS拍攝的史蒂芬森2-18與其母星團史蒂芬森2（左上）。; Credit: 斯特拉斯堡大學/CNRS (2003)
觀測資料; 曆元 J2000
星座	盾牌座
星官
赤經	18h 39m 02.3709s
赤緯	-06° 05′ 10.5357″
視星等（V）
特性
演化階段	紅超巨星
光譜分類	~M6
視星等 (G)	15.2631±0.0092
視星等 (J)	7.150
視星等 (H)	4.698
視星等 (K)	2.9
天體測定
自行 (μ)	赤經：−3.045±0.511 mas/yr ; 赤緯：−5.950±0.480 mas/yr
視差 (π)	−0.0081 ± 0.3120 mas
距離	18,900 ly ; (5,800 pc)
詳細資料
半徑	2,150 R☉
亮度	437,000 (90,000 – 630,000) L☉
溫度	3,200 K
其他命名
	史蒂芬森2-18、史蒂芬森2DFK1、St 2-18、RSGC2-18、2MASS J18390238-0605106、IRAS 18363-0607
參考資料庫
SIMBAD	資料

史蒂文森2-18(英語:Stephenson 2-18)是位於盾牌座方向的一個紅特超巨星。距離地球大約20,000光年，在斯蒂芬森2 疏散星團視線方向。^[7].

觀測數據

它是目前已知體積最大的恆星。其測量的半徑是我們的太陽半徑的2158倍 ^[5]. 估計有效溫度為3,200克爾文，光度為440,000 太陽光度。 ^[5].

參見

註釋

^ 假設恆星有效溫度為5772開爾文條件下按斯特凡-波茲曼定律計算：
${\sqrt {(5,772/3,200)^{4}*10^{5.64}}}=2,149.58\ R\odot$
^ 有時會被誤記為RSGC1-F01

參考文獻

^ ^1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 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中此天體在蓋亞望遠鏡第二批數據發佈的記錄
^ Negueruela, I.; González-Fernández, C.; Dorda, R.; Marco, A.; Clark, J. S. The population of M-type supergiants in the starburst cluster Stephenson 2. Eas Publications Series. 2013, 60: 279. Bibcode:2013EAS....60..279N. arXiv:1303.1837 . doi:10.1051/eas/1360032.
^ ^3.0 ^3.1 ^3.2 Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T.; Fowler, J.; Gizis, J.; Howard, E.; Huchra, J.; Jarrett, T.; Kopan, E. L.; Kirkpatrick, J. D.; Light, R. M.; Marsh, K. A.; McCallon, H.; Schneider, S.; Stiening, R.; Sykes, M.; Weinberg, M.; Wheaton, W. A.; Wheelock, S.; Zacarias, N. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003). VizieR On-line Data Catalog: II/246. Originally Published in: 2003yCat.2246....0C. 2003, 2246: 0. Bibcode:2003yCat.2246....0C.
^ ^4.0 ^4.1 ^4.2 Humphreys, Roberta M.; Helmel, Greta; Jones, Terry J.; Gordon, Michael S. Exploring the Mass Loss Histories of the Red Supergiants. The Astronomical Journal. 2020, 160 (3): 145. Bibcode:2020AJ....160..145H. arXiv:2008.01108 . doi:10.3847/1538-3881/abab15.
^ ^5.0 ^5.1 ^5.2 ^5.3 ^5.4 Fok, Thomas K. T; Nakashima, Jun-ichi; Yung, Bosco H. K; Hsia, Chih-Hao; Deguchi, Shuji. Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters. The Astrophysical Journal. 2012, 760 (1): 65. Bibcode:2012ApJ...760...65F. arXiv:1209.6427 . doi:10.1088/0004-637X/760/1/65.
^ Deguchi, Shuji; Nakashima, Jun-Ichi; Zhang, Yong; Chong, Selina S. N.; Koike, Kazutaka; Kwok, Sun. SiO and H2O Maser Observations of Red Supergiants in Star Clusters Embedded in the Galactic Disk. Publications of the Astronomical Society of Japan. 2010, 62 (2): 391–407. Bibcode:2010PASJ...62..391D. arXiv:1002.2492 . doi:10.1093/pasj/62.2.391.
^ Davies, B.; Figer, D. F.; Kudritzki, R. P.; MacKenty, J.; Najarro, F.; Herrero, A. A Massive Cluster of Red Supergiants at the Base of the Scutum‐Crux Arm. The Astrophysical Journal. 2007, 671 (1): 781–801. Bibcode:2007ApJ...671..781D. arXiv:0708.0821 . doi:10.1086/522224.

這是一篇與恆星相關的小作品。您可以透過編輯或修訂擴充其內容。

[radius-6] 假設恆星有效溫度為5772開爾文條件下按斯特凡-波茲曼定律計算：
${\sqrt {(5,772/3,200)^{4}*10^{5.64}}}=2,149.58\ R\odot$

[mistake-8] 有時會被誤記為RSGC1-F01

[dr2-1] 1.0 ^1.1 ^1.2 ^1.3 ^1.4 ^1.5 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中此天體在蓋亞望遠鏡第二批數據發佈的記錄

[negueruela2013-2] Negueruela, I.; González-Fernández, C.; Dorda, R.; Marco, A.; Clark, J. S. The population of M-type supergiants in the starburst cluster Stephenson 2. Eas Publications Series. 2013, 60: 279. Bibcode:2013EAS....60..279N. arXiv:1303.1837 . doi:10.1051/eas/1360032.

[2mass-3] 3.0 ^3.1 ^3.2 Cutri, R. M.; Skrutskie, M. F.; Van Dyk, S.; Beichman, C. A.; Carpenter, J. M.; Chester, T.; Cambresy, L.; Evans, T.; Fowler, J.; Gizis, J.; Howard, E.; Huchra, J.; Jarrett, T.; Kopan, E. L.; Kirkpatrick, J. D.; Light, R. M.; Marsh, K. A.; McCallon, H.; Schneider, S.; Stiening, R.; Sykes, M.; Weinberg, M.; Wheaton, W. A.; Wheelock, S.; Zacarias, N. VizieR Online Data Catalog: 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003). VizieR On-line Data Catalog: II/246. Originally Published in: 2003yCat.2246....0C. 2003, 2246: 0. Bibcode:2003yCat.2246....0C.

[humphreys2020-4] 4.0 ^4.1 ^4.2 Humphreys, Roberta M.; Helmel, Greta; Jones, Terry J.; Gordon, Michael S. Exploring the Mass Loss Histories of the Red Supergiants. The Astronomical Journal. 2020, 160 (3): 145. Bibcode:2020AJ....160..145H. arXiv:2008.01108 . doi:10.3847/1538-3881/abab15.

[thomas-5] 5.0 ^5.1 ^5.2 ^5.3 ^5.4 Fok, Thomas K. T; Nakashima, Jun-ichi; Yung, Bosco H. K; Hsia, Chih-Hao; Deguchi, Shuji. Maser Observations of Westerlund 1 and Comprehensive Considerations on Maser Properties of Red Supergiants Associated with Massive Clusters. The Astrophysical Journal. 2012, 760 (1): 65. Bibcode:2012ApJ...760...65F. arXiv:1209.6427 . doi:10.1088/0004-637X/760/1/65.

[deguchi2010-7] Deguchi, Shuji; Nakashima, Jun-Ichi; Zhang, Yong; Chong, Selina S. N.; Koike, Kazutaka; Kwok, Sun. SiO and H2O Maser Observations of Red Supergiants in Star Clusters Embedded in the Galactic Disk. Publications of the Astronomical Society of Japan. 2010, 62 (2): 391–407. Bibcode:2010PASJ...62..391D. arXiv:1002.2492 . doi:10.1093/pasj/62.2.391.

[Davies20072-9] Davies, B.; Figer, D. F.; Kudritzki, R. P.; MacKenty, J.; Najarro, F.; Herrero, A. A Massive Cluster of Red Supergiants at the Base of the Scutum‐Crux Arm. The Astrophysical Journal. 2007, 671 (1): 781–801. Bibcode:2007ApJ...671..781D. arXiv:0708.0821 . doi:10.1086/522224.

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觀測資料曆元 J2000
2MASS拍攝的史蒂芬森2-18與其母星團史蒂芬森2（左上）。 Credit: 斯特拉斯堡大學/CNRS (2003)
星座	盾牌座
星官
赤經	18^h 39^m 02.3709^s^[1]
赤緯	-06° 05′ 10.5357″^[1]
視星等（V）
特性
演化階段	紅超巨星
光譜分類	~M6^[2]
視星等 (G)	7001152631000000000♠15.2631±0.0092^[1]
視星等 (J)	7.150^[3]
視星等 (H)	4.698^[3]
視星等 (K)	2.9^[3]
天體測定

自行 (μ)	赤經：2999695500000000000♠−3.045±0.511^[1] mas/yr 赤緯：2999405000000000000♠−5.950±0.480^[1] mas/yr
視差 (π)	−0.0081 ± 0.3120^[1] mas
距離	18,900^[4] ly (5,800^[4] pc)

詳細資料

半徑	2,150^[5]^[a] R_☉
亮度	437,000^[5] (90,000^[6] – 630,000^[4]^[b]) L_☉
溫度	3,200^[5] K

其他命名
史蒂芬森2-18、史蒂芬森2DFK1、St 2-18、RSGC2-18、2MASS J18390238-0605106、IRAS 18363-0607
參考資料庫
SIMBAD	資料