The Isochronal Age Scale of Young Moving Groups in the Solar Neighbourhood

Abstract

We present a self-consistent, absolute isochronal age scale for young (≲ 200 Myr), nearby (≲ 100 pc) moving groups, which is consistent with recent lithium depletion boundary ages for both the β Pic and Tucana-Horologium moving groups. This age scale was derived using a set of semi-empirical pre-main-sequence model isochrones that incorporate an empirical colour-T eff relation and bolometric corrections based on the observed colours of Pleiades members, with theoretical corrections for the dependence on logg. Absolute ages for young, nearby groups are vital as these regions play a crucial role in our understanding of the early evolution of low-and intermediate-mass stars, as well as providing ideal targets for direct imaging and other measurements of dusty debris discs, substellar objects and, of course, extrasolar planets.