Breaking Degeneracies in Formation Histories by Measuring Refractory Content in Gas Giants

Abstract Relating planet formation to atmospheric composition has been a long-standing goal of the planetary science community. So far, most modeling studies have focused on predicting enrichment heavy elements and C/O ratio in giant atmospheres. Although this framework provides useful constraints potential locations gas exoplanets, carbon oxygen measurements alone are not enough determine where given originated. Here, we show that characterizing abundances refractory (e.g., silicon iron) can break these degeneracies. Refractory present solid phase throughout disk, their therefore reflect solid-to-gas accretion during formation. We introduce new parameterizes exoplanets form three ratios: Si/H, O/Si, C/Si. Si/H traces is loosely equivalent earlier notions “metallicity.” For O/Si C/Si, global picture variation with distance time based what know from solar system meteorites an updated understanding variations thermal processing within protoplanetary disks. ultrahot Jupiters ideal targets for characterization using as measure refractories, oxygen, phase. Finally, propose hot silicate clouds low water might accreted envelopes between soot line snow line.