Yesterday was the second day of this year's white dwarf workshop. I gave my presentation yesterday, and it went well. (In a few weeks, video of the talks will be online here. Just not yet.)
Much of the first half of the day focused on physics. While a lot of astronomy often may appear to involve describing objects, one of our main goals in astronomy is to understand the physics behind all of the beautiful objects in the sky.
White dwarfs are a great physics laboratory. Because white dwarfs can contain as much matter as the sun squeezed into a ball only the size of the Earth, the material is very dense. It is so dense, in fact, that white dwarfs create forms of matter that do not exist on the Earth. White dwarfs are one of the few ways to study the physics of these extreme environments.
As I mentioned briefly yesterday, white dwarfs slowly cool over time. The matter in their cores, which starts off as a dense hot plasma, also cools off. When it cools enough, the matter changes from a plasma to a solid, in fact a crystal. Since white dwarfs are made out of ...