Ternary diagram showing the possible composition of K2-265 b. The thick black line indicates the allowed composition of the planet inferred from the central values of the mass and radius of the planet, and the dashed lines denote the deviations from this line allowed by the 1σ uncertainties on the fundamental parameters. The red line and area show the compositions compatible with the planetary bulk Fe/Si ratio derived for K2-265 b from the stellar value. Compositions of the Earth and Mercury are shown for reference.