Evolution of evaporating lava planets
File(s)
Author(s)
Curry, Alfred
Type
Thesis
Abstract
The interiors of rocky planets are heavily influenced by planet formation and hugely affect the subsequent evolution of planets; therefore understanding them is essential. A particular class of detected system that may be useful in probing rocky interior composition is the catastrophically evaporating planets. These planets are detected through dust tails which originate from the planets' molten surfaces. Linking the composition of the tails to that of the bulk planet requires understanding the evolution of the underlying planets.
In this thesis, I develop a 1D interior model and use it to model the catastrophically evaporating planets. The model includes simultaneous structural and thermal evolution alongside mass loss and appropriate boundary conditions for these super-heated planets. I find that, despite their high irradiation, the planets are likely able to mostly solidify and so the outflows only originate from a thin lava pool close to the surface.
Using this as a premise, I go on to study the evolution of the lava pool-atmosphere system under mass loss. I find that once enough material is removed from the pool a steady state is reached, where the composition of the outflowing atmosphere matches that of material melted into the pool. I also show that this situation may be common, even amongst fairly high-mass planets.
By considering how frequently one might expect to observe mass loss from the catastrophically evaporating planets, I predict the occurrence of the underlying population of planets needed to produce the number of observations. This is of interest because the progenitors are thought to be low mass and thus difficult to detect in conventional surveys. I find that the population is either in line with, or much higher than, detected larger planets of the same substellar temperatures, depending on model assumptions.
In this thesis, I develop a 1D interior model and use it to model the catastrophically evaporating planets. The model includes simultaneous structural and thermal evolution alongside mass loss and appropriate boundary conditions for these super-heated planets. I find that, despite their high irradiation, the planets are likely able to mostly solidify and so the outflows only originate from a thin lava pool close to the surface.
Using this as a premise, I go on to study the evolution of the lava pool-atmosphere system under mass loss. I find that once enough material is removed from the pool a steady state is reached, where the composition of the outflowing atmosphere matches that of material melted into the pool. I also show that this situation may be common, even amongst fairly high-mass planets.
By considering how frequently one might expect to observe mass loss from the catastrophically evaporating planets, I predict the occurrence of the underlying population of planets needed to produce the number of observations. This is of interest because the progenitors are thought to be low mass and thus difficult to detect in conventional surveys. I find that the population is either in line with, or much higher than, detected larger planets of the same substellar temperatures, depending on model assumptions.
Version
Open Access
Date Issued
2024-03
Date Awarded
2024-06
Copyright Statement
Creative Commons Attribution NonCommercial NoDerivatives Licence
Advisor
Mohanty, Subhanjoy
Owen, James
Sponsor
Science and Technology Facilities Council (Great Britain)
Grant Number
ST/V506734/1
Publisher Department
Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)