M50 (疏散星团)

M 50
M 50
	当天狼星在南方天空时，梅西耶50位于天狼星北方8°和东方3°的角上（观察时的左侧）。
观测资料 (J2000 历元)
星座	麒麟座
赤经	07h 02m 47.5s
赤纬	−08° 20′ 16″
距离	2,870 ly（881 pc）
视星等 (V)	5.9
视大小 (V)	16.0′
物理特征
质量	> 285 M☉ M☉
半径	8.9 ly（2.73 pc）
估计年龄	140 Myr
其他特征	M50, NGC 2323, Cr 124, C 0700-082, OCl 559
	相关条目：疏散星团、NGC天体表

M50或梅西耶50，也称为NGC 2323，是位于麒麟座的一个疏散星团。它可能在1711年之前就被卡西尼发现，梅西耶在1772年4月5日观测比拉彗星时，又再度独立发现它。它有时也被描述或心形或钝箭头^[3]。

M50距离地球大约2,900光年^[2]，虽然与大犬座 OB1星协接近，但估计关系并不紧密^[4]。它的核心半径为5.9 ly（1.8 pc）^[6]，范围为17.8 ly（5.46 pc）^[4]。这个星团有508个已确认成员和109个可能的成员；它们的总质量超过7032566736750000000♠285 M_☉，平均恒星密度是每立方秒差距1.3颗恒星^[4]。星团的历史大约有1.4亿年^[1]，有两颗大质量的白矮星^[7]和两颗特殊恒星^[8]。

图集

梅西耶50
天狼星和M41（右下角）、M50（左上）和NGC 2360 （左下）。

参考资料和注解

^ ^1.0 ^1.1 ^1.2 ^1.3 Frolov, V. N.; et al, Investigation of the open star cluster NGC 2323 (M50) based on the proper motions and photometry of its constituent stars, Astronomy Letters, February 2012, 38 (2): 74–86, Bibcode:2012AstL...38...74F, doi:10.1134/S106377371202003X.
^ ^2.0 ^2.1 Kharchenko, N. V.; et al, Astrophysical parameters of Galactic open clusters, Astronomy and Astrophysics, 2005, 438 (3): 1163–1173, Bibcode:2005A&A...438.1163K, arXiv:astro-ph/0501674  , doi:10.1051/0004-6361:20042523.
^ ^3.0 ^3.1 ^3.2 Thompson, Robert; Thompson, Barbara, Illustrated Guide to Astronomical Wonders: From Novice to Master Observer, DIY science, O'Reilly Media, Inc.: 321, 2007, ISBN 978-0596526856
^ ^4.0 ^4.1 ^4.2 ^4.3 ^4.4 Claria, J. J.; et al, Photometric study of the open cluster NGC 2323, Astronomy and Astrophysics Supplement, February 1998, 128: 131–138, Bibcode:1998A&AS..128..131C, doi:10.1051/aas:1998130 
^ M 50. SIMBAD. 斯特拉斯堡天文资料中心.
^ Sharma, Saurabh; et al, Mass Functions and Photometric Binaries in Nine Open Clusters, The Astronomical Journal, May 2008, 135 (5): 1934–1945, Bibcode:2008AJ....135.1934S, arXiv:0803.0122  , doi:10.1088/0004-6256/135/5/1934.
^ Cummings, Jeffrey D.; et al, Two Massive White Dwarfs from NGC 2323 and the Initial-Final Mass Relation for Progenitors of 4 to 6.5 M, The Astrophysical Journal, February 2016, 818 (1): 13, Bibcode:2016ApJ...818...84C, arXiv:1601.03053  , doi:10.3847/0004-637X/818/1/84, 84.
^ Paunzen, E.; et al, Photoelectric search for peculiar stars in open clusters. XV. Feinstein 1, NGC 2168, NGC 2323, NGC 2437, NGC 2547, NGC 4103, NGC 6025, NGC 6633, Stock 2, and Trumpler 2, Astronomy & Astrophysics, April 2014, 564: 8, Bibcode:2014A&A...564A..42P, arXiv:1403.3538  , doi:10.1051/0004-6361/201423521, A42.

^ Eight out of ninety degrees south of the celestial equator. Thus its light reaches all parts of the Earth, down to a good minimal cumulation 15° above the horizon, on the unobstructed southern horizons of the 67th parallel north. This rules out Iceland and the north coasts of the two northernmost continents.

外部链接

Messier 50 - at Deep Sky Videos （页面存档备份，存于互联网档案馆）
Messier 50, SEDS Messier pages （页面存档备份，存于互联网档案馆）
M50 Image by Waid Observatory （页面存档备份，存于互联网档案馆）
WikiSky上关于M50 (疏散星团)的内容：DSS2, SDSS, GALEX, IRAS, 氢α, X射线, 天文照片, 天图, 文章和图片

NASA Astronomy Picture of the Day: Open Cluster M50 (28 January 1997)

[Frolov2012-1] 1.0 ^1.1 ^1.2 ^1.3 Frolov, V. N.; et al, Investigation of the open star cluster NGC 2323 (M50) based on the proper motions and photometry of its constituent stars, Astronomy Letters, February 2012, 38 (2): 74–86, Bibcode:2012AstL...38...74F, doi:10.1134/S106377371202003X.

[kharchenko2005-3] 2.0 ^2.1 Kharchenko, N. V.; et al, Astrophysical parameters of Galactic open clusters, Astronomy and Astrophysics, 2005, 438 (3): 1163–1173, Bibcode:2005A&A...438.1163K, arXiv:astro-ph/0501674  , doi:10.1051/0004-6361:20042523.

[Thompson2007-4] 3.0 ^3.1 ^3.2 Thompson, Robert; Thompson, Barbara, Illustrated Guide to Astronomical Wonders: From Novice to Master Observer, DIY science, O'Reilly Media, Inc.: 321, 2007, ISBN 978-0596526856

[Claria1998-5] 4.0 ^4.1 ^4.2 ^4.3 ^4.4 Claria, J. J.; et al, Photometric study of the open cluster NGC 2323, Astronomy and Astrophysics Supplement, February 1998, 128: 131–138, Bibcode:1998A&AS..128..131C, doi:10.1051/aas:1998130 

[SIMBAD-6] M 50. SIMBAD. 斯特拉斯堡天文资料中心.

[Sharma2008-7] Sharma, Saurabh; et al, Mass Functions and Photometric Binaries in Nine Open Clusters, The Astronomical Journal, May 2008, 135 (5): 1934–1945, Bibcode:2008AJ....135.1934S, arXiv:0803.0122  , doi:10.1088/0004-6256/135/5/1934.

[Cummings2016-8] Cummings, Jeffrey D.; et al, Two Massive White Dwarfs from NGC 2323 and the Initial-Final Mass Relation for Progenitors of 4 to 6.5 M, The Astrophysical Journal, February 2016, 818 (1): 13, Bibcode:2016ApJ...818...84C, arXiv:1601.03053  , doi:10.3847/0004-637X/818/1/84, 84.

[Paunzen2014-9] Paunzen, E.; et al, Photoelectric search for peculiar stars in open clusters. XV. Feinstein 1, NGC 2168, NGC 2323, NGC 2437, NGC 2547, NGC 4103, NGC 6025, NGC 6633, Stock 2, and Trumpler 2, Astronomy & Astrophysics, April 2014, 564: 8, Bibcode:2014A&A...564A..42P, arXiv:1403.3538  , doi:10.1051/0004-6361/201423521, A42.

[2] Eight out of ninety degrees south of the celestial equator. Thus its light reaches all parts of the Earth, down to a good minimal cumulation 15° above the horizon, on the unobstructed southern horizons of the 67th parallel north. This rules out Iceland and the north coasts of the two northernmost continents.

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