球状星团NGC 6752

2024年10月25日

Globular Star Cluster NGC 6752
Image Credit & Copyright: Massimo Di Fusco, Aygen Erkaslan

Explanation: Some 13,000 light-years away toward the southern constellation Pavo, the globular star cluster NGC 6752 roams the halo of our Milky Way galaxy. Over 10 billion years old, NGC 6752 follows clusters Omega Centauri, 47 Tucanae, and Messier 22 as the fourth brightest globular in planet Earth’s night sky. It holds over 100 thousand stars in a sphere about 100 light-years in diameter. Telescopic explorations of NGC 6752 have found that a remarkable fraction of the stars near the cluster’s core, are multiple star systems. They also reveal the presence of blue straggle stars, stars which appear to be too young and massive to exist in a cluster whose stars are all expected to be at least twice as old as the Sun. The blue stragglers are thought to be formed by star mergers and collisions in the dense stellar environment at the cluster’s core. This sharp color composite also features the cluster’s ancient red giant stars in yellowish hues. (Note: The bright, spiky blue star about 8 o’clock from the cluster center is a foreground star along the line-of-sight to NGC 6752)

Tomorrow’s picture: pixels in space

球状星团NGC 6752
影像提供与版权: Massimo Di Fusco, Aygen Erkaslan

说明: 漫游于银河系银晕里的球状星团NGC 6752，位在南天的孔雀座方向约13,000光年远处。高龄超过100亿年的NGC 6752，是继半人马座奥米茄星团、杜鹃座47和M22之后，地球夜空中第四亮的球状星团。在NGC 6752里，10多万颗成员星拥挤在约100光年的球形空间里。NGC 6752的望远镜观测发现，球团核心有相当大比例的恒星是多星系统。此外，也找到一些蓝掉队星（离散星），而这类恒星的质量太大，也太年轻，按理说不应出现在这个恒星年龄至少要比太阳大2倍以上的星团里。目前认为这些蓝掉队星，是在星团核心的高恒星密度环境里，经由合并与碰撞所形成的。这张清晰的彩色组合影像，也呈现了这个星团泛黄的古老红巨星。 （附注：星团内约8点钟方向的带芒泛蓝天体，是位于NGC 6752视线方向的前景恒星。）

明日的图片: pixels in space