White Dwarfs in Omega Centauri: Preliminary Evidence
  We present accurate and deep multiband B,R,Halpha data for the globular cluster Omega Cen collected with the Advanced Camera for Surveys on HST. The photometric catalogue includes more than one million stars. By adopting severe selection criteria we identified more than 600 bona fide White Dwarfs (WDs). Empirical evidence suggests that a small sample of WDs are Halpha-bright. The comparison between WD isochrones and observations shows a reasonable agreement at fainter magnitudes and a mismatch at the brighter ones. 
G. Bono, M. Monelli, P. B. Stetson, P. G. Prada Moroni, R. Buonanno,   A. Calamida, I. Ferraro, G. Iannicola, C. E. Corsi, a...