Star Clusters, Page 74: [Previous Page] [Next Page] [Class Home Page] Textbook pages 404 - 417

Population I and II Stars

Globular Clusters and other old stars reside in the Halo. They can be found to rotate in any direction, clock-wise or counter-clock-wise. They can also have ``cigar-shaped'' or very round orbits. These stars are called Population II stars.

Population II stars actually help us to DEFINE what the Halo is.







Population I stars are quite different. Our Sun is a Population I star, and lies in the plane of our galaxy. Like all stars that live in the disk, it moves clock wise as seen from the north.


Stars which are part of the Bulge have properties somewhere between Population I and II. They are mostly old stars, and their distribution is rather round (not flat like the Disk). However, they mostly rotate in the same general direction as the Disk stars (the Pop I stars).