Ayaka Okuya
I am a JSPS (Japan Society for the Promotion of Science) Postdoctoral Fellow in the Astronomy and Astrophysics group at the University of Warwick, working with Dimitri Veras. My research interests focus on solid exoplanets, including Earth, and I primarily work within the white dwarf research group from a planetary science perspective. I am also involved in the exoplanets research group and the discs research group. My CV is in this link.
Research Interests
My research aims to uncover the properties and origins of solid planets, including our own Earth. Recent exoplanet observations have revealed that planets composed mainly of solid materials are ubiquitous. However, are these solid exoplanets truly Earth-like? The composition of such planets provides essential clues for characterizing them, as it determines their atmospheres and surfaces and preserves the signatures of their formation and evolution. The most common approach to observationally infer the bulk composition of an exoplanet is to use its bulk density, but this single quantity alone cannot uniquely constrain the composition.
On the other hand, environments where planets are disintegrating have been discovered in recent years. My research is focused on developing new theoretical frameworks and observational methodologies that enable us to constrain planetary interior compositions down to elemental and mineralogical levels and reconstruct their formation histories. One of the most promising environments is the debris disks and evolved planetary systems around white dwarfs. A quarter to half of all white dwarfs exhibit metals (elements heavier than helium) in their atmospheres, and many show surrounding dust and gas disks. These metals and disks are thought to originate from planetary-sized solid bodies that were scattered close to the star, tidally disrupted to form debris disks, and subsequently accreted onto the white dwarf.
To accurately infer the composition and orbital properties of these progenitor bodies from observations, I primarily work on theoretically modeling the evolution of dust and gas accretion disks around white dwarfs. The evolution of such disks involves various physical and chemical processes. In particular, I focus on incorporating phase changes and interactions between dust and gas, as well as collisions among dust particles, into my models. Additionally, I am extending my white dwarf disk research into observational domains. This includes spectral analyses of dust disks based on the optical properties of minerals, and predictions of gas disk observability with future infrared space telescopes. Through these efforts, I aim to provide additional constraints on planetary compositions.
I also have experience studying the spectroscopic observability of catastrophically evaporating rocky exoplanets and modeling the climates of planets in binary star systems.
You can find my publications list on my public ADS library.
