Genesis of Trojans in PDS 70 b potentially hunted with ALMA

Dust is key to find planets during the first million of years of stars life. The planet-star interactions imprint signatures in the protoplanetary disk that serve as hints to locate them. Some of those substructures are rings, gaps or elliptical arms, and they have been recently observed in tens of disks with high angular resolution ALMA images. As predicted by hydrodynamical simulations, one of the most common signatures that evidence the presence of forming planets is dust in co-rotation trapped in the Lagrangian points of the protoplanets. In this talk, we present the first tentative detection of co-orbital dust trapped within the orbit of a confirmed protoplanet: a mass up to 0.7 M_Moon of around 1 mm-sized dust particles accumulated in the Lagrangian point L₅ of the iconic planet PDS 70 b. We outline how future observations will confirm or reject its co-orbital nature, and how such a discovery can contribute to understand planetary formation and evolution processes. If confirmed, this would be the first direct evidence of the nursery of Trojan bodies supporting their formation theories and opening the window to their detection in mature systems.