Are the rings in protoplanetary disks carved by planets?
In plain words
Images of young disks show bright rings and dark gaps. Hidden young planets could carve them, but other processes can make rings too.
Precise statement
ALMA images show axisymmetric dust rings and gaps at $10\text{-}100\,\mathrm{AU}$ in $\sim 1\,\mathrm{Myr}$ disks. Determine for the population whether gaps are opened by embedded planets of ~ 0.1-1 Jupiter masses or by non-planetary processes (condensation fronts, magnetohydrodynamic zonal flows, secular gravitational instability). The answer is the fraction of gaps with a planetary origin.
What would settle it
Direct imaging or gas-kinematic detection of planets inside gaps for a representative disk sample, with upper limits for the rest.
Status in the literature
Unverified note
Planets were imaged inside disk gaps in PDS 70 (2018-2019) and WISPIT 2 (WISPIT 2b in 2025, a second planet WISPIT 2c confirmed in 2026); for most ringed disks no planet has been detected.