The 4MOST Survey of Young Stars (4SYS)

Most nearby young stars (with ages < 100 Myr) in the Galactic disc no longer reside in their dense, clustered birthplaces; they are found all around us. The 4MOST Survey of Young Stars will identify a representative sample of about 10⁵ young, low-mass stars within 500 pc of the Sun and will measure their chemistry, 3D kinematics and ages in order to: trace the spatial and dynamical evolution of star-forming structures; quantify the star formation rate and chemical inhomogeneity in the local disc; vastly expand the number of identified young stars for exoplanetary studies; and provide huge coeval samples to improve young stellar evolutionary models.