Labels:text | screenshot OCR: GLOBULAR CLUSTERS A GLOBULAR CLUSTER is a densely packed group of stars, ranging in number from tens of thousands up to hundreds of thousands. Globular clusters are roughly spherical and typically 100 light years across. Their stars are concentrated at the center of the cluster. There are about 150 known globular clusters in our galaxy, most of which lie in a halo surrounding the galactic nucleus. The stars in globular clusters are old, Population II stars. M 13, IN HERCULES This cluster is 160 light years across. It has hundreds of thousands of stars held together by gravity. Many FACT FILE of its stars are 10 billion years old.
