Dynamical age Tucana-Horologium

We take advantage of the state-of-the-art astrometry delivered by the third data release of the Gaia space mission combined with precise radial velocity measurements obtained from high-resolution spectroscopy to investigate the dynamical age of the association.

We perform an extensive traceback analysis using a combination of different samples of cluster members, metrics to evaluate the minimum size of the association in the past and models for the galactic potential to integrate the stellar orbits back in time. The dynamical age of 38.5^+1.6^_-8.0_Myr that we derive in this paper is consistent with the various age estimates obtained from isochrone fitting in the literature (30-50Myr) and reconciles, for the first time, the dynamical age of the Tucana-Horologium association with the age obtained from lithium depletion (~40Myr).