- As a cluster ages, the mass of the main-sequence turnoff
stars decreases. By determining the mass of the main-sequence
turnoff stars, we get the age of the cluster.
- This is one of the ways we have studied the age of the
Universe and the formation history of the Galaxy. The objects in
the Galactic Halo are at least 10 billion and perhaps
as old as 14 billion years old. There is an interesting story
that we will talk about in detail later that has to do with
the correlation of the abundance of the elements in stars with their
age.
Michael Bolte
Sat Feb 14 22:10:25 PST 1998