梅西耶69

M 69
	哈伯太空望遠鏡拍攝的M69；視場3.5弧分 ; Credit: NASA/STScI/WikiSky
觀測數據(J2000 曆元)
分類	V
星座	人馬座
赤經	18h 31m 23.10s
赤緯	−32° 20′ 53.1″
距離	29 kly（8.8 kpc）
視星等 (V)	+8.31
視直徑(V)	10′.8
物理性質
Mass	2.0×105 M☉ M☉
半徑	45 ly
金屬量	–0.78 dex
估計年齡	13.06 Gyr
其它名稱	GCl 96, M69, NGC 6637
	參見：球狀星團，球狀星團表

M69或梅西耶69，也稱為NGC 6637，是在人馬座南側的一個球狀星團.^[a]。它的位置在箕宿三(人馬座ε)東北方2.5度，在口徑50mm的雙筒望遠鏡中隱約可見。梅西耶在1780年8月31日發現它，當晚它同時也發現了另一個球狀星團M70。當時，他正在尋找尼可拉·路易·拉卡伊在1751-2年間於南非觀測時所描述的天體，並認為重新發現了它，但並不清楚拉卡伊描述的是否就是M69^[8]。

M69距離地球28,700光年^[3]，距離銀河核心5,200光年^[9]，在空間中的半徑為45光年^[6]。它是一個金屬量相對豐富的球狀星團，很可能是核球的成員^[10]。它的質量為7005200000000000000♠200000 太陽質量，半質量半徑為11.6 ly^[5]，核心半徑為29.2 ly，潮汐半徑為91.9 ly^[3]。它的中心有一個明亮的光度密度7003646000000000000♠6,460 L_☉·pc⁻³（表示每立方釐米）^[9]。與它類似的近鄰，同為球狀星團的M70之間的距離可能只有1,800光年^[11]。

圖集[编辑]

就球狀星團而言，M69是有記錄以來金屬量最高的星團之一^[12]。
以箭頭指示M69位置的星圖 (羅伯托·穆拉) 。

參考資料和註解[编辑]

^ Shapley, Harlow; Sawyer, Helen B., A Classification of Globular Clusters, Harvard College Observatory Bulletin, August 1927, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.
^ ^2.0 ^2.1 Goldsbury, Ryan; et al, The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters, The Astronomical Journal, December 2010, 140 (6): 1830–1837, Bibcode:2010AJ....140.1830G, arXiv:1008.2755 , doi:10.1088/0004-6256/140/6/1830.
^ ^3.0 ^3.1 ^3.2 ^3.3 Kharchenko, N. V.; et al, Global survey of star clusters in the Milky Way. II. The catalogue of basic parameters, Astronomy and Astrophysics, 2013, 558: 8, Bibcode:2013A&A...558A..53K, S2CID 118548517, arXiv:1308.5822 , doi:10.1051/0004-6361/201322302, A53.
^ ^4.0 ^4.1 NGC 6637. SIMBAD. 斯特拉斯堡天文資料中心.
^ ^5.0 ^5.1 Mandushev, G.; et al, Dynamical masses for galactic globular clusters, Astronomy and Astrophysics, December 1991, 252: 94, Bibcode:1991A&A...252...94M.
^ ^6.0 ^6.1 From trigonometry: distance × sin( diameter_angle / 2 ) = 28,700 × 0.00157 = 45 ly. radius
^ ^7.0 ^7.1 Forbes, Duncan A.; Bridges, Terry, Accreted versus in situ Milky Way globular clusters, Monthly Notices of the Royal Astronomical Society, May 2010, 404 (3): 1203–1214, Bibcode:2010MNRAS.404.1203F, S2CID 51825384, arXiv:1001.4289 , doi:10.1111/j.1365-2966.2010.16373.x.
^ Thompson, Robert Bruce; Thompson, Barbara Fritchman, Illustrated Guide to Astronomical Wonders: From Novice to Master Observer, Maker Media, Inc., 2007, ISBN 978-1680451917
^ ^9.0 ^9.1 Piotto, G.; et al, HST color-magnitude diagrams of 74 galactic globular clusters in the HST F439W and F555W bands, Astronomy and Astrophysics, September 2002, 391 (3): 945–965, Bibcode:2002A&A...391..945P, S2CID 17333985, arXiv:astro-ph/0207124 , doi:10.1051/0004-6361:20020820.
^ Heasley, J. N.; et al, Hubble Space Telescope Photometry of the Metal-rich Globular Clusters NGC 6624 and NGC 6637, The Astronomical Journal, August 2000, 120 (2): 879–893, Bibcode:2000AJ....120..879H, doi:10.1086/301461 .
^ Frommert, Hartmut; Kronberg, Christine, Globular Cluster M69, SEDS Messier pages (Students for the Exploration and Development of Space (SEDS)), July 20, 2011 [2018-12-03], （原始内容存档于2015-04-21）.
^ Cosmic riches. ESA/Hubble Picture of the Week. [3 October 2012]. （原始内容存档于2017-07-08）.

^ 在每天升起的天體中，無論是白天還是夜間，它在過子午線時要能達到15°以上高度角，才能詳細的觀察。因此，北緯43度線是能觀測這個星團的最北位置(90°減32°再減15°。)

外部連結[编辑]

Messier 69, Galactic Globular Clusters Database page （页面存档备份，存于互联网档案馆）
WikiSky上关于梅西耶69的内容：DSS2, SDSS, GALEX, IRAS, 氢α, X射线, 天文照片, 天图, 文章和图片

天球赤道座標： 18^h 31^m 23.23^s，−32° 20′ 52.7″

[hcob849_11-1] Shapley, Harlow; Sawyer, Helen B., A Classification of Globular Clusters, Harvard College Observatory Bulletin, August 1927, 849 (849): 11–14, Bibcode:1927BHarO.849...11S.

[aj140_6_1830-2] 2.0 ^2.1 Goldsbury, Ryan; et al, The ACS Survey of Galactic Globular Clusters. X. New Determinations of Centers for 65 Clusters, The Astronomical Journal, December 2010, 140 (6): 1830–1837, Bibcode:2010AJ....140.1830G, arXiv:1008.2755 , doi:10.1088/0004-6256/140/6/1830.

[Kharchenko2013-3] 3.0 ^3.1 ^3.2 ^3.3 Kharchenko, N. V.; et al, Global survey of star clusters in the Milky Way. II. The catalogue of basic parameters, Astronomy and Astrophysics, 2013, 558: 8, Bibcode:2013A&A...558A..53K, S2CID 118548517, arXiv:1308.5822 , doi:10.1051/0004-6361/201322302, A53.

[simbad-4] 4.0 ^4.1 NGC 6637. SIMBAD. 斯特拉斯堡天文資料中心.

[Mandushev1991-5] 5.0 ^5.1 Mandushev, G.; et al, Dynamical masses for galactic globular clusters, Astronomy and Astrophysics, December 1991, 252: 94, Bibcode:1991A&A...252...94M.

[approx-6] 6.0 ^6.1 From trigonometry: distance × sin( diameter_angle / 2 ) = 28,700 × 0.00157 = 45 ly. radius

[mnras404_3_1203-7] 7.0 ^7.1 Forbes, Duncan A.; Bridges, Terry, Accreted versus in situ Milky Way globular clusters, Monthly Notices of the Royal Astronomical Society, May 2010, 404 (3): 1203–1214, Bibcode:2010MNRAS.404.1203F, S2CID 51825384, arXiv:1001.4289 , doi:10.1111/j.1365-2966.2010.16373.x.

[Thompson2007-9] Thompson, Robert Bruce; Thompson, Barbara Fritchman, Illustrated Guide to Astronomical Wonders: From Novice to Master Observer, Maker Media, Inc., 2007, ISBN 978-1680451917

[Piotto2002-10] 9.0 ^9.1 Piotto, G.; et al, HST color-magnitude diagrams of 74 galactic globular clusters in the HST F439W and F555W bands, Astronomy and Astrophysics, September 2002, 391 (3): 945–965, Bibcode:2002A&A...391..945P, S2CID 17333985, arXiv:astro-ph/0207124 , doi:10.1051/0004-6361:20020820.

[Heasley2000-11] Heasley, J. N.; et al, Hubble Space Telescope Photometry of the Metal-rich Globular Clusters NGC 6624 and NGC 6637, The Astronomical Journal, August 2000, 120 (2): 879–893, Bibcode:2000AJ....120..879H, doi:10.1086/301461 .

[Hartmut2011-12] Frommert, Hartmut; Kronberg, Christine, Globular Cluster M69, SEDS Messier pages (Students for the Exploration and Development of Space (SEDS)), July 20, 2011 [2018-12-03], （原始内容存档于2015-04-21）.

[esa/hubble-13] Cosmic riches. ESA/Hubble Picture of the Week. [3 October 2012]. （原始内容存档于2017-07-08）.

[8] 在每天升起的天體中，無論是白天還是夜間，它在過子午線時要能達到15°以上高度角，才能詳細的觀察。因此，北緯43度線是能觀測這個星團的最北位置(90°減32°再減15°。)

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