My personal webpage.
I'm a theoretical astrophysicist in the Astrophysics group. I hold a senior Royal Society University Research Fellowship. Previously I was a Hubble Fellow at the Institute for Advanced Study in Princeton and a CITA fellow in Toronto. My primary interests include planet formation, extra-solar planets and accretion disc physics.
The discovery of extra-solar planets (exoplanets) has been a staggering advance in astronomy in the last two decades. We have now know that the diversity of planetary systems is far my diverse than we could have even dreamed about. My current interests are understanding how close-in super-earth/mini-neptunes formed and evolve. The origin of these planets which orbit their stars with periods from hours to several months is one of the most interesting puzzles to have arisen from NASA's Kepler mission. The fact that these planets reside so close to their stars also means their atmospheres are subject to intense irradiation, orders of magnitude above what our solar system planets experience. This irradiation drives vigorous atmospheric escape, "evaporating" planets over there long lifetime. By understanding how exoplanet atmosphere's escape we can build a picture of what the planets looked like in the past, gaining insights into how they formed.
At the earliest phases of the planet formation process, forming planets are embedded in a thin rotating gas disc which surrounds the young star. This planet-forming disc (or protoplanetary disc) provides the environment in which planets grow and migrate. In the last few years we have been able to take images of these discs at unprecedented resolution, resolving scales smaller than the size of the Earth's orbit. These images have revealed a smorgasbord of structures, which may or may not be linked to forming planets residing in these discs. A complete understanding of what creates these structures is missing and linking them to the properties of planets remains elusive. By using a combination of analytic theory to study hydrodynamic instabilities and simulations I hope to build a picture of how these structures we see in discs relate to and to not planet formation. We are just seeing the tip of the iceberg with these new images. The community has only studied a small fraction of the nearby protoplanetary discs, over the next 5 years the number will grow considerably.
Cummins DP, Owen JE, Booth RA, 2022, Extreme pebble accretion in ringed protoplanetary discs, Monthly Notices of the Royal Astronomical Society, Vol:515, ISSN:0035-8711, Pages:1276-1295
et al., 2022, An APEX search for carbon emission from NGC 1977 proplyds, Monthly Notices of the Royal Astronomical Society, Vol:512, ISSN:0035-8711, Pages:2594-2603
et al., 2022, One year of AU Mic with HARPS: I - measuring the masses of the two transiting planets, Monthly Notices of the Royal Astronomical Society, Vol:512, ISSN:0035-8711, Pages:3060-3078
et al., 2022, TESS hunt for young and maturing exoplanets (THYME). VI. an 11 Myr giant planet transiting a very-low-mass star in lower centaurus crux, The Astronomical Journal, Vol:163, ISSN:0004-6256, Pages:156-156
et al., 2022, The California-Kepler survey. X. The radius gap as a function of stellar mass, metallicity, and age, The Astronomical Journal, Vol:163, ISSN:0004-6256, Pages:179-179