Signatures of an intermediate-age metal-rich bulge population
  We have determined detailed elemental abundances and stellar ages for a sample of now 38 microlensed dwarf and subgiant stars in the Galactic bulge. Stars with sub-solar metallicities are all old and have enhanced alpha-element abundances -- very similar to what is seen for local thick disk stars. The metal-rich stars on the other hand show a wide variety of stellar ages, ranging from 3-4 Gyr to 12 Gyr, and an average around 7-8 Gyr. The existence of young and metal-rich stars are in conflict with recent photometric studies of the bulge which claim that the bulge only contains old stars. 
T. Bensby, S. Feltzing, A. Gould, J. A. Johnson, M. Asplund, D.   Ad\'en, J. Mel\'endez, J. G. Cohen, I. Thompson, S. Lucate...
astro-ph.GA