animated_figures.md

Cherubim et al. 2025 animated figures

All figures shown here were generated from data discussed in Cherubim et al. 2025. The plotted data come from Monte Carlo simulations using a coupled atmospheric escape-magma ocean/equilibrium chemistry model (IsoFATE+Atmodeller). The selected figures correspond to energy-limited EUV-driven/radiative recombination-limited photoevaporation of planets around an early M type star.

Figure 1

Atmospheric composition trends for simulated planets around M stars over time. Colors are chosen arbitrarily and color intensity indicates species molar concentrations as a function of orbital period vs. planet radius (left) and atmospheric scale height (right). Each group corresponds to atmospheres with molar concentration $\geq 50\%$, except H₂O, for which the cutoff is 5%. Red indicates O₂, green indicates CO₂, yellow indicates CO, blue indicates H₂O, orange indicates He, and grey indicates H₂. Planets trend toward greater oxidation with smaller radii and shorter orbital periods as a result of atmospheric escape-driven fractionation and magma ocean volatile exchange. H₂O-rich planets are exceptional in that they are not well confined in period-raidus space and typically do not reach atmospheric molar concentrations above ~ 10% as a result of our dry start assumption.

Figure 4

Atmospheric composition trends for simulated planets around M stars over time. x_i indicates the molar concentration of a given species at each point in time. Brown circles indidate planets that have completely lost their atmospheres. Squares indicate planets that have elevated D/H ratios greater than 10 x protosolar D/H (Lodders et al. 2003). Marker size corresponds to the indicated planet mass bins. Some planets show marginal increases in radius after several Gyr as a result of late-stage volatile outgassing from the solidifying magma ocean. Most planets have non-zero mantle melt fractions by 5 Gyr.

Supplemental Figure 1

Atmospheric composition trends for simulated planets around M stars over time. Percentages reflect fractions of all simulated planets with the corresponding dominant atmospheric species. Planets with atmospheres dominated by molecular oxygen (O₂ worlds) are the most common type of non-H₂ planet, i.e. planets with secondary atmospheres that are largely sculpted by escape and interior exchange. This prediction is robust to many assumptions discussed in Cherubim et al. 2025.

Supplemental Figure 2

Same as Supplemental Figure 1, but only planets with non-H₂ atmospheres are considered, i.e. planets with secondary atmospheres that are largely sculpted by escape and interior exchange.