Read section 8.5b and answer questions 8-10.
Figure 8.10 Globular Cluster Properties (NGC 5139)
Composition: Population II stars
Lifespan: +15 billion years
Number of stars: 10,000 to 1,000,000 stars
Globular clusters are gravitationally bound concentrations of stars. Spectroscopic study of globular clusters shows that they have much less heavy element than stars that form in the disks of galaxies, such as the Sun. Thus, globular clusters are very old and formed from an earlier generation of stars.
Figure 8.11: Distribution of 146 Globular Clusters