Oral title: Accurate Ages of Bulge Globular Clusters from Deep and Proper-motion-cleaned HST and 
Gemini CMDs

Oral abstract: Alpha-enhanced ([alpha/Fe] >~ +0.3) and moderately metal-poor ([Fe/H] <~ -1.0) bulge 
globular clusters (GCs) with blue horizontal branches are probable relics of the early star formation 
in the innermost Galactic regions. To determine the ages of such stellar systems, normally suffering 
by severe extinction and strong field contamination, we have employed multi-epoch photometry from 
HST (optical) and Gemini (near-infrared, using GSAOI+GeMS) to build proper-motion-cleaned and 
deep colour-magnitude diagrams (CMDs). By means of Bayesian isochrone fits, we have confirmed 
that NGC6522, NGC6626 and HP1 are among the oldest GCs in the Galaxy, with ages between 12.5 
and 13.0 Gyr. Metallicities from high-resolution spectroscopy and distances from RR Lyrae stars 
allowed us to better constraint the ages and the helium abundance. Orbital analysis of these clusters 
suggest that the early fast chemical enrichment in the bulge can be imprinted in stars at 
Galactocentric distances of ~ 3.0 kpc.