Consolidating CHEOPS and preparing for PLATO: Exoplanet studies in the 2020s

In 2019 the European Space Agency successfully launched CHEOPS, a spacecraft dedicated to high-precision photometric studies of extrasolar planets. This will be followed in around 2026 by the more capable PLATO.

Together with the ongoing Gaia mission, which is enabling excellent characterisation of exoplanets´ host stars, these missions are providing exquisite data about nearby planetary systems: especially the radii and orbital properties of their planets.In this project I have been working to understand the orbital dynamical evolution of observed exoplanet systems, and the relation between a planetary system and its host star.

I now seek an extension, to focus on the following areas:1.

To determine how the class of "ultra-short period" planets, with extremely short orbital periods of less than 1 day, arrive on their very small orbits close to the star.

These planetary systems are becoming increasingly well-characterised by CHEOPS and complementary radial-velocity measurements.

Here I will model the combination of interactions between planets and tidal interaction between the planet and the host star, to simulate the long-term evolution of systems observed by my colleagues.2.

To study the correlations between the properties of a planetary system and the kinematics of its host star within the Galaxy.

Here I will use knowledge of stellar motions provided by Gaia to study the kinematic properties of stars observed by CHEOPS and how they relate to properties of the planetary system like whether a planet is rocky or gaseous.3.

To study the end of planetary systems´ lives when stars have become white dwarfs, and in particular whether the collisions of asteroids in the discs often detected around white dwarf stars will be detectable by the PLATO spacecraft.

Many white dwarfs are known to be surrounded by dust discs that show infrared variability, which may be caused by the collision or tidal disruption of asteroids.

Here I will simulate the expected photometric signatures of such collisions in visible light, in preparation for the PLATO mission.Together, these will help deepen our understanding of all aspects of a planetary system´s history, from formation, through migration and long-term orbital changes, to their ultimate fates around white dwarfs.