I am a Warwick Prize fellow in the Warwick Astronomy and Astrophysics group working on white dwarf stars. My academic CV can be found here. My personal website can be found here. My full list of publications can be found here.

Research

I am primarily concerned with the study of white dwarfs. This type of stellar remnant represents the end-state for the 95%+ of main-sequence stars with masses below 8 Solar-masses, which will not undergo a core-collapse supernova. Instead, while in the giant-star phase of evolution, the outer 50% of the star will be ejected in an intense stellar wind. The remaining 50%, no longer producing pressure via nuclear fusion in the stellar interior, is unable to contend with the intense gravitational forces. The core thus collapses until the quantum-phenomenon known as electron-degeneracy pressure can balance gravity. The result is a hot (100,000 K), immensely dense, Earth-sized object -- the white dwarf.
The interior of a typical white dwarf is mostly (99%) a mix of carbon-oxygen ions in a sea of degenerate electrons. Around this, is an envelope of helium (about 1% of the mass), and usually, a final shroud of hydrogen (0.01% of the mass). Our telescopes of course can only directly see the outer-most layers and what they're made of. Therefore the interior composition is constrained from our theoretical understanding of how stars evolve, but also from observations of pulsating white dwarfs where waves travelling through the interior make it to the surface, providing information on the density of the central carbon-oxygen core.

Because white dwarfs do not fuse-nuclei in their cores, they instead radiate away their internal energy, at first cooling rapidly, and then much more slowly the temperature of the white dwarf outer layers decrease. The oldest white dwarfs known to the Milky Way can have cooled from an initial 100000 K to a relatively cool 3000 K (only half the temperature at the surface of the Sun). Because the processes that affect white dwarf cooling rates are fairly well understood, the coolest (and thus oldest) white dwarfs provide firm constraints on the age of the Galactic disk.