武仙大球状星团

2023年9月1日

The Great Globular Cluster in Hercules
Image Credit & Copyright: Serge Brunier, Jean-François Bax, David Vernet OCA/C2PU

Explanation: In 1716, English astronomer Edmond Halley noted, “This is but a little Patch, but it shows itself to the naked Eye, when the Sky is serene and the Moon absent.” Of course, M13 is now less modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky. Sharp telescopic views like this one reveal the spectacular cluster’s hundreds of thousands of stars. At a distance of 25,000 light-years, the cluster stars crowd into a region 150 light-years in diameter. Approaching the cluster core, upwards of 100 stars could be contained in a cube just 3 light-years on a side. For comparison, the closest star to the Sun is over 4 light-years away. The remarkable range of brightness recorded in this image follows stars into the dense cluster core.

Tomorrow’s picture: wisdom in a flower

武仙大球状星团
影像提供与版权: Serge Brunier, Jean-François Bax, David Vernet OCA/C2PU

说明: 在1716年，英国天文学家哈雷撰写如下的注记：”它只是夜空的一个小亮斑，不过当夜空清朗无月时，用肉眼就能看见它“。如今我们当然知道这所谓的“它“是M13，一个位于武仙座方向的大球状星团，同时也是北天最明亮的球状星团之一。类似上面的这种清晰望远镜影像，显示这个的庞大星团拥有数十万颗成员星。以这个星团25,000光年的距离来换算，星团的成员星拥挤在直径约150光年的范围内。尤其在星团的中心附近，边长3光年的立方空间内就有100颗恒星。相较之下，离太阳最近的恒星超过4光年远。

明日的图片: wisdom in a flower