Planet gap opening across stellar masses

Gaps and rings are now ubiquitously found by high-resolution ALMA observations and planets are commonly invoked as an explanation. In this contribution I discuss how the minimum planet mass needed to open a gap varies across different stellar host masses and distances from the star. Naively gap opening around low-mass stars should be possible for lower mass planets, giving us a look into the young, low-mass planet population. Using dusty hydrodynamical simulations, I find however the opposite behaviour, as a result of the fact that discs around low-mass stars are geometrically thicker: gap opening around low-mass stars can require more massive planets. Depending on the theoretical isochrone employed to predict the relationship between stellar mass and luminosity, the gap opening planet mass could also be independent of stellar mass, but in no case I find that gap opening becomes easier around low-mass stars. This would lead to the expectation of a lower incidence of such structures in lower mass stars, since exoplanet surveys show that low-mass stars have a lower fraction of giant planets. More generally, this study enables future imaging observations as a function of stellar mass to be interpreted using information on the mass versus luminosity relations of the observed samples.