Related papers: Coupled Thermal and Compositional Evolution of Pho…
Kepler's observation shows that many of the detected planets are super-Earths. They are inside a range of critical masses overlapping the core masses (2-20 $M_{\bigoplus}$), which would trigger the runaway accretion and develop the gas…
(abridged) When stripped from their hydrogen-rich envelopes, stars with initial masses between $\sim$7 and 11 M$_\odot$ develop massive degenerate cores and collapse. Depending on the final structure and composition, the outcome can range…
We constrain the planetary atmospheric mass fraction at the time of the dispersal of the protoplanetary disk and the evolution of the stellar rotation rate for a dozen multi-planet systems that host sub-Neptunes and/or super-Earths. We…
The primordial internal structures of gas giant planets are unknown. Often giant planets are modeled under the assumption that they are adiabatic, convective, and homogeneously mixed, but this is not necessarily correct. In this work, we…
Throughout their lives, short period exoplanets (<100 days) experience X-ray and extreme-UV (XUV) stellar irradiation that can heat and photoionize planets' upper atmospheres, driving transonic outflows. This photoevaporative mass loss…
Understanding the surface temperature and interior structure of cold-to-temperate sub-Neptunes is critical for assessing their habitability, yet direct observations are challenging. In this study, we investigate the impact of water…
The hot Neptune orbiting around GJ 436 is a unique example of an intermediate mass planet. Its close-in orbit suggests that the planet has undergone migration and its study is fundamental to understanding planet formation and evolution. As…
Atmospheric escape is thought to significantly influence the evolution of exoplanets, especially for sub-Jupiter planets on short orbital periods. Theoretical models predict that hydrodynamic escape could erode the atmospheres of such…
(abridged) Search for planets around main-sequence (MS) stars more massive than the Sun is hindered by their hot and rapidly spinning atmospheres. This obstacle has been sidestepped by radial-velocity surveys of those stars on their post-MS…
Atmospheric mass loss is thought to induce the bimodality in the small planet population as we observe it today. Observationally, active mass loss can be traced by excess absorption in spectral lines of lighter species, such as the hydrogen…
Atmospheric escape driven by extreme ultraviolet (EUV) radiation is a critical process shaping the evolution of close-in exoplanets. Recent observations have detected helium triplet absorption in numerous (>20) close-in exoplanets,…
We present a new numerical framework to model the formation and evolution of giant planets. The code is based on the further development of the stellar evolution toolkit Modules for Experiments in Stellar Astrophysics (MESA). The model…
The morphology of planetary nebulae emerging from the common envelope phase of binary star evolution is investigated. Using initial conditions based on the numerical results of hydrodynamical simulations of the common envelope phase it is…
The brightness of Neptune is often found to be in accordance with an adiabatic interior, while the low luminosity of Uranus challenges this assumption. Here we apply revised equation of state data of hydrogen, helium, and water and compute…
To describe the evaporation status of the extrasolar planets, we propose to consider an energy diagram in which the potential energy of the planets is plotted versus the energy received by the upper atmosphere. Here we present a basic…
Context: The thermal and chemical structures of the upper atmospheres of planets crucially influence losses to space and must be understood to constrain the effects of losses on atmospheric evolution. Aims: We develop a 1D first-principles…
Extreme helium stars are very rare low-mass supergiants in a late stage of evolution. They are probably contracting to become white dwarfs following a violent phase of evolution which caused them to become hydrogen-deficient giants,…
Short period planets are subject to intense energetic irradiations from their stars. It has been shown that this can lead to significant atmospheric mass-loss and create smaller mass planets. Here, we analyse whether the evaporation…
By means of hydrodynamical models we do the first investigations of how the properties of planetary nebulae are affected by their metal content and what can be learned from spatially unresolved spectrograms of planetary nebulae in distant…
Using density functional molecular dynamics simulations, we determine the equation of state for hydrogen-helium mixtures spanning density-temperature conditions typical of giant planet interiors, ~0.2-9 g/cc and 1000-80000 K for a typical…