Determine whether GEMS have different metallicities from FGK giant planets

Determine whether the metallicity of giant exoplanets around M-dwarf stars differs from that of giant exoplanets orbiting FGK stars, thereby testing whether the apparent heavy-element deficit of GEMS is real rather than a consequence of the small observational sample.

Background

The paper discusses evidence that the inferred heavy-element masses of giant planets around M-dwarf stars may be lower than those of comparable planets around FGK stars. However, the available sample is very small, and another study found no evidence for a planetary mass–metallicity dependence. Consequently, the observational distinction between the bulk metallicities of GEMS and FGK giant planets remains unresolved.

Atmospheric metallicity measurements from JWST and the future Ariel mission are presented as a way to reduce degeneracies in interior-structure models and enlarge the sample available for testing this question.