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泰尔让7

天球赤道座标星图 19h 17m 43.5s, −34° 39′ 27″
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泰尔让7
哈伯太空望远镜拍摄的泰尔让7,视直径3.5’。
Credit: NASA、ESA、和A. Sarajedini(佛罗里达大学)。Acknowledgement: Gilles Chapdelaine
观测数据(J2000 历元)
星座人马座
赤经19h 17m 43.92s[1]
赤纬-34° 39′ 27.8″[1]
距离75.7 kly(23.2 kpc[2]
视星等 (V)12.0[2]
视直径(V)7′.3[2]
物理性质
半径160 光年[a]
VHB17.76[3]
估计年龄7.5 Gyr[4]
值得注意的特色young extragalactic globular
其它名称Ter 7,[4] GCl 109.1[5]

泰尔让7是松散和年轻的球状星团,被认为起源于人马座矮椭球星系(Sag DEG)并与之有物理上的关联。相较之下它是富金属,它的金属量是[Fe/H] = -0.6[6],并且估计年龄是75亿岁[4]。泰尔让7有少量的([Ni/Fe]=-0.2),因为有着相似的化学特征,这支持它是人马座矮椭球星系的成员[7]。它有丰富的蓝掉队星,并且强烈的朝向中心集中[8]。它的平均亮度分布在Mv = -5.05.[9]。它的半光度半径(Rh)= 6.5秒差距[10]

历史

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泰尔让7是法国天文学家阿戈普·泰尔让英语Agop Terzan在1968年发现的[11]最亮的[12]六个球状星团之一[12]

年轻的球状星团

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几乎所有的银河系的银晕的球状星团是同时形成(12-15 Gyr)。 即使是位于远处的NGC 2419(距离银河中心约100 kpc)也有相似的年龄。这种趋势也适用于大麦哲伦星系天炉座矮星系(来自银河中心的约140 kpc)发现的球状团的年龄。

注解

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  1. ^ 75.7 kly × tan( 7′.3 / 2 ) = 160 ly. radius

参考资料

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  1. ^ 1.0 1.1 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可免费查阅, doi:10.1088/0004-6256/140/6/1830. 
  2. ^ 2.0 2.1 2.2 Terzan 7 @ seds, (原始内容存档于2002-10-24) 
  3. ^ Wilson, Barbara, Obscure Globulars, July 2, 1995 [2016-01-23], (原始内容存档于2016-01-13) 
  4. ^ 4.0 4.1 4.2 Geisler, Doug; Wallerstein, George; Smith, Verne V.; Casetti-Dinescu, Dana I., Chemical Abundances and Kinematics in Globular Clusters and Local Group Dwarf Galaxies and Their Implications for Formation Theories of the Galactic Halo, The Publications of the Astronomical Society of the Pacific, September 2007, 119 (859): 939–961, Bibcode:2007PASP..119..939G, arXiv:0708.0570可免费查阅, doi:10.1086/521990 
  5. ^ SIMBAD Astronomical Object Database. Results for Terzan 7. [2008-01-27]. (原始内容存档于2020-05-17). 
  6. ^ Sbordone, L.; Bonifacio, P.; Marconi, G.; Buonanno, R.; Zaggia, S., Family ties: Abundances in Terzan 7, a Sgr dSph globular cluster, Astronomy and Astrophysics, July 3, 2005, 437 (3): 905–910, Bibcode:2005A&A...437..905S, arXiv:astro-ph/0505307可免费查阅, doi:10.1051/0004-6361:20042315 
  7. ^ Sbordone, L.; Bonifacio, P.; Marconi, G.; Buonanno, R., Chemical abundances in Terzan 7, Memorie della Societa Astronomica Italiana, 2004, 75: 396, Bibcode:2004MmSAI..75..396S 
  8. ^ Held, Enrico V.; Rosenberg, Alfred; Saviane, Ivo; Momany, Yazan, 写于Pucon, Chile, Geisler, D.; Grebel, E.K.; Minniti, D. , 编, The Globular Cluster Terzan 7 in the Sagittarius Dwarf Spheroidal Galaxy, Astronomical Society of the Pacific (San Francisco), March 12–16, 2001: 165 (2002), Bibcode:2002IAUS..207..165H 
  9. ^ van den Bergh, Sidney, The Luminosity Distribution of Globular Clusters in Dwarf Galaxies, The Astronomical Journal, July 2007, 134 (1): 344–345, Bibcode:2007AJ....134..344V, arXiv:0704.2226可免费查阅, doi:10.1086/518868 
  10. ^ van den Bergh, Sidney, Young Globular Clusters and Dwarf Spheroidals, The Astrophysical Journal, February 2000, 530 (2): 777–782, Bibcode:2000ApJ...530..777V, arXiv:astro-ph/9910243可免费查阅, doi:10.1086/308413 
  11. ^ Terzan, Agop, Six nouveaux amas stellaires (Terzan 3-8) dans la region DU centre de la Voie lactee et les constellations DU Scorpion et DU Sagittaire, C.R. Acad. Sci., 1968, 267 (Ser. B): 1245–1248, Bibcode:1968CRASB.267.1245T 
  12. ^ 12.0 12.1 Gottlieb, Steve, Sky and Telescope, August 1, 2000, 100 (2): 112, ISSN 0037-6604  缺少或|title=为空 (帮助)