"The STARS2 project aims at modelling on massively parallel supercomputers in a self-consistent and three-dimensional way, the complex, time dependent and nonlinear dynamics operating in the Sun and stars. In particular we wish to understand how stars generate the wide variety of magnetic activity that is observed, with the Sun - given its proximity and its influence on our technical society - playing a central role in characterizing, studying, and constraining the dynamical processes acting in stellar convection and radiation zones. Studying the solar-stellar connection is crucial because it will allow us to understand why depending on the spectral type of the star considered, this activity can be cyclic, irregular, or simply modulated. The mechanism thought to be at the origin of the magnetism seen in late type stars is likely to be linked to dynamo action in the upper convective layers of such stars. The simultaneous existence in stars of convective turbulent motions, of rotation and its associated shear layers, favour the emergence of a small and/or large scale magnetic field through induction. For more massive stars, possessing a convective core, understanding the interaction between the dynamo generated magnetic field in the core and the magnetic field of their radiative envelope constitute major challenges in stellar fluid dynamics. To achieve these challenging scientific goals, the STARS2 project propose to federate a team of young bright scientists around the PI and to perform and to analyse sophisticated and more realistic high performance global MHD numerical simulations of the Sun and other stellar spectral types. These simulations are at the front-edge of current research in astrophysics, they require the use of the latest class of supercomputers available in Europe and will lead to real scientific breakthroughs. Understanding the interactions between convection, turbulence, shear, rotation and magnetic fields in stars IS the main goal of this project."