Description
The impact of ALMA in planet formation studies has been apparent since the discovery of the complex disc substructure, often made of rings and gaps in dust continuum images, that may be the signature of the presence of a planet embedded in the disc. Now, ALMA is revealing its full capabilities to work as a "planet detection machine", where the planet properties can be potentially constrained with high precision thanks to the study of the gas kinematics in the vicinity of the planet, that bears the imprint of the planet gravitational field. In addition, the high spectral and spatial resolution observations that are needed to this effect can bring further information on deviations from Keplerianity due to other sources, such as the disc’s own self-gravity. In this talk, (1) I will describe how to model semi-analytically the velocity perturbations induced by a planet in the gas, which is an essential ingredient to provide accurate fitting of the planet properties from gas kinematics and (2) I will describe our recent dynamical measurement of the disc mass in Elias 2-27 by using large scale deviations from Keplerianity in the gas rotation curve, confirming that the disc in this source is massive and is the likely responsible for the observed spiral structure in the dust continuum.
