White Dwarfs

A lot of astronomical research is directed towards either determining the distance to various things or by trying to determine how old they are. Since stars and galaxies don't come with convenient labels, we have to try various nefarious ways of extracting this data from what they do give us, namely the amount and energy distribution of the light they emit.

White dwarfs are particularly useful in this regard. These are the burned out remnants of stars like the sun. They've burnt all their hydrogen and helium to carbon and oxygen and are now slowly cooling down, radiating whatever thermal heat is left from their previous incarnations. By making a stellar model we can try to determine how old each white dwarf is based on how cool it is.

White dwarfs are very useful for determining the age of old stellar populations because the oldest populations have had the most time to burn up their stars and form white dwarfs i.e. white dwarfs are basically the fossil record of star formation. The problem is, of course, that being old and cool, they're also pretty faint and it takes a lot of telescope time to find them.

I and colleagues are busy trying to model the evolution of white dwarfs in the local stellar neighbourhood and nearby stellar associations called globular clusters, with the aim of trying to determine the ages of the various components of the Galaxy.