2024/12/23 by Artyom Aguichine, Aguichine, Artyom, Fortney, Jonathan +9 · 4 citations
Earth and Planetary Sciences · #Geological Studies and Exploration
paper · doi:10.48550/arxiv.2412.17945
Evolutionary tracks from the Steam Worlds Evolution (SWE) model (Aguichine et al. 2025). Link to manuscript: https://ui.adsabs.harvard.edu/abs/2025ApJ...988..186A/abstract Model summary:Earth-like core (32.5% iron-sulfur alloy, 67.5% mantle with Earth-like Fe/Si ratio)Pure H2O envelope and pure H2O atmosphere connected at Pb = 1000 barParameters:ST: Stellar Type (M or G), for radiative transfer in the atmosphereWMF: Water Mass Fraction, between 0.001 and 1Teq: Equilibrium temperature (K), between 500 K and 700 KMp: Planet mass (Me), between 0.2 ME and 20.0 MEAge: Host star age (Gyr), between 0.001 Gyr and 20 Gyr, assuming the planet formed at t0 = 1 Myr (can be adjusted)Model outputs:Rb: Planet radius (RE) at 1000 barRb: Planet radius (RE) at 20 mbar, pressure level where pure steam is opaque at 1 micronRb: Planet radius (RE) at 1 µbar, pressure level of aerosols/haze formationTb: Temperature (K) at 1000 bar)Tint: Intrinsic temperature (K), nominal values are between 10 K and 400 Ksenv: Specific entropy of H2O in the envelope (in J/K/kg)I/MR2: Moment of inertia factorSources of energy for the cooling, expressed as luminosities (in W):Lenv: energy from the H2O envelope (thermal + gravitational)Lrad: radiogenic heat produced in the coreLcore: thermal energy of the coreLgrav: gravitational energy of the coreutot: total energy of the planet (J), obtained by fully integrating thermal (cp*T*dm) and gravitational energyBy construction:Lenv + Lrad + Lcore + Lgrav = (4 * Pi * Rp**2) * (sigmaSB * Tint**4)d utot / d t = -Lint + Lrad NB: The last line of each track represents an estimate of the time until "full exhaustion" (see paper for details).