We can determine the age of a star by the way sounds move within it.
Dying Embers
Determining the age of galaxies and globular clusters can be a bit of a challenge. There are several ways you can get a handle on galactic age. One of these is by looking at the ratio of red dwarf stars to larger stars. Red dwarf stars burn very slowly, so their lifetimes can be 100 billion years or more. Given that the universe is only about 14 billion years old, this means that red dwarfs haven’t had time to die off. Larger stars die off faster, so the higher the proportion of red dwarf stars, the older the galaxy should be.
Star Dates
Determining the age of a star poses a bit of a challenge for astronomers. After all, stars exist over a timescale of billions of years, and they are light years away. We can’t use radiometric dating like we do for rocks and other objects on Earth. So just how do we determine the age of a star? It turns out that there are several ways, and it’s getting easier to do.