Detection of Continuum Submillimeter Emission Associated with Candidate Protoplanets

We present the discovery of a spatially unresolved source of submillimeter continuum emission (λ = 855 μm) associated with a young planet, PDS 70 c, recently detected in Hα emission around the 5 Myr old T Tauri star PDS 70. We interpret the emission as originating from a dusty circumplanetary disk with a dust mass between 2 × 10−3 M⊕ and 4.2 × 10−3 M⊕. Assuming a standard gas-to-dust ratio of 100, the ratio between the total mass of the circumplanetary disk and the mass of the central planet would be between 10−4 and 10−5. Furthermore, we report the discovery of another compact continuum source located 0farcs074 ± 0farcs013 southwest of a second known planet in this system, PDS 70 b, that was previously detected in near-infrared images. We speculate that the latter source might trace dust orbiting in proximity of the planet, but more sensitive observations are required to unveil its nature.