Cosmochronology within the stellar neighbourhood: Leaving no star and planet behind

The stellar population near the Sun, which contains the brightest specimens of almost all types of stars and planets, is a key research area that remains poorly explored. The spacecraft Gaia has provided, for the first time, a near complete census of stars and white dwarfs within 100 pc, but a full understanding of the local stellar population is still a major challenge. From this project and my involvement in the next generation multi-object spectroscopic surveys 4MOST and WEAVE, I will obtain medium resolution optical spectroscopy of all stars within 100 pc. I will also conduct theoretical development to improve our understanding of how white dwarf and low-mass star evolve. Modelling the combined astrometric, photometric and spectroscopic data for these 400,000 stellar objects, including crucial sub-samples of wide binaries as well as white dwarfs with well constrained ages, I propose a novel and ambitious method to improve our knowledge of single and binary stellar evolution with a particular focus on stellar ages. This will unlock the enormous potential of using stellar remnants as cosmic clocks to trace the local stellar formation history for the Galactic disk, halo and associated clusters, which will help to comprehend the chemical and dynamical evolution of the Milky Way on a larger scale. The assembly of galaxies like our own is itself paramount to understand the evolution of the low redshift Universe. I will also study evolved planetary systems that are currently being accreted in the convection zone of their white dwarf hosts, providing a direct and unique window into the beginning and evolution of rocky planet formation in our Galaxy. The project will be at the forefront of the stellar revolution triggered by Gaia and multi-object spectroscopic surveys, as well as major forthcoming and deeper surveys such as LSST and Euclid.