Extended Data Fig. 9: Modelled atmosphere in equilibrium with a magma ocean on 55 Cnc e.

a, Partial pressure of gases for the volatile content of H, C, N and S as Earth’s early magma ocean (solid lines) and 3% H content (dashed lines), simulated by a magma ocean–atmosphere partitioning and chemical equilibrium/speciation model⁴⁴. b, Emission spectra and associated pressure–temperature profiles for a 200-bar atmosphere with Earth-like C–H–N–S volatile abundance ratios in the atmosphere–magma ocean system, simulated by our atmospheric radiative transfer and chemistry model. c, Same as panel b but for a 1-bar atmosphere and a H abundance ratio in the atmosphere–magma ocean system reduced to 3% of the standard cases. The NIRCam data are offset to match with the best-fit model (64 ppm for panel b and 58 ppm for panel c). The total number of data points is 30 for the interpretation of the χ² values.