White dwarfs are the slowly fading embers left behind when a star exhausts its fuel supply. Measurements of the masses and temperatures of white dwarfs allow us to study the end stages of stellar evolution, such as how much mass a star loses as a red giant and what mass of star explodes as a supernova instead of forming a white dwarf. I am working on building a large sample of white dwarfs to study in regard to these questions. For something completely different, I also work on studying groups of galaxies at distances of several billion light-years (z~0.2-0.75, for those who speak redshifts), as I look for evidence of how the galaxies in these groups have changed over time.
I run a website called Professor Astronomy in an attempt to describe the exciting daily life of professional scientists and astronomers. I also assist with a yearly continuing education course for science teachers at McDonald Observatory, in which we introduce teachers to research involving white dwarfs using a series of activities closely tied to national science teaching standards. The teachers are encouraged to use these activities with their own students to illustrate basic concepts in physics.