Volatile composition of the HD 169142 disk and its embedded plantet

Determining the abundances of key volatiles within protoplanetary disks is essential for establishing connections between the composition of disks and the planets that form within them. This talk explores the chemistry of HD 169142, a Herbig Ae star hosting a molecule-rich disk with an embedded protoplanet. Using high-resolution ALMA data and advanced thermochemical modelling, the elemental abundances of carbon, oxygen, and sulfur are characterised at small spatial scales. Particular focus is placed on analysing the first-ever detection of SiS in a protoplanetary disk, with emission near the protoplanet vastly exceeding model predictions. This suggests a potential origin in shocked gas or localised outflows, offering a unique probe into ongoing planet formation processes. Our findings are contextualised in terms of the potential atmospheric composition of the embedded planet, and highlight the diagnostic power of sulfur-bearing molecules as probes of protoplanetary disk chemistry.