The white dwarf distance to the globular cluster 47 Tucanae and its age

We present a new determination of the distance (and age) of the Galactic gl obular cluster 47 Tucanae (NGC 104) based on the fit of its white dwarf (WD ) cooling sequence with the empirical fiducial sequence of local WD with kn own trigonometric parallax, following the method described by Renzini and c ollaborators. Both the cluster and the local WDs were imaged with HST WFPC2 using the same instrument setup. We obtain an apparent distance modulus of consistent with (m-M)(v) = 13.27 +/- 0.14, previous ground-based determina tions and shorter than that found using Hipparcos subdwarfs. Coupling our d istance determination with a new measure of the apparent magnitude of the m ain-sequence turnoff based on our HST data, we derive an age of 13 +/- 2.5 Gyr.