Identification of a Nearby Stellar Association in theHipparcos Catalog: Implications for Recent, Local Star Formation

The TW Hydrae Association (~55 pc from Earth) is the nearest known region of recent star formation. Based primarily on the Hipparcos catalog, we have identified a group of nine or 10 comoving star systems at a common distance (~45 pc) from Earth that appear to comprise another, somewhat older association (``the Tucanae Association''). Together with ages and motions recently determined for some nearby field stars, the existence of the Tucanae and TW Hydrae Associations suggests that the Sun is now close to a region that was the site of substantial star formation only 10-50 Myr ago. The TW Hydrae Association represents a final chapter in the local star formation history.