White dwarfs in NGC 6791: Avoiding the helium flash

We propose that the anomalously bright white dwarf luminosity function observed in NGC 6791 (Bedin et al.) is the consequence of the formation of 0.5 M circle dot white dwarfs with helium cores instead of carbon cores. This may happen if mass loss during the ascent of the red giant branch is strong enough to prevent a star from reaching the helium flash. Such a model can explain the slower white dwarf cooling (relative to standard models) and fits naturally with scenarios advanced to explain extreme horizontal branch stars, a population of which are also found in this cluster.