Role of stellar Mg/Si ratios in gas-giant planet mineralogy

Characterize the role of the stellar Mg/Si ratio in determining the mineralogical composition of gas-giant planets.

Background

The Mg/Si ratio influences silicate mineralogy by affecting whether magnesium is primarily incorporated into pyroxene or olivine. The paper measures Mg/Si ratios in early-F and A-type planet hosts and compares them with stars without known planets, but the sample is dominated by gas-giant planet systems.

Because the mineralogical consequences of stellar Mg/Si variations are much better established for rocky planets than for gas giants, the authors explicitly identify the relevance of this ratio to gas-giant mineralogy as unresolved. Establishing this relationship would help interpret the observed abundance patterns and connect stellar composition to planetary composition.

References

We should caution that our current sample includes mostly gas-giant planets, for which the role of the stellar $\rm {Mg/Si}$ ratio in their mineralogy is still far to be fully understood.

— Signatures of rocky debris accretion in AF-Type planet hosts  (2609.04790 - Maldonado et al., 4 Sep 2026) in Section 4, subsection “Migration and formation environment”