  We examine catalogs of white dwarfs (WDs) and find that there are sufficient
number of massive WDs, M_WD > 1.35Mo, that might potentially explode as type Ia
supernovae (SNe Ia) in the frame of the core degenerate scenario. In the core
degenerate scenario a WD merges with the carbon-oxygen core of a giant star,
and they form a massive WD that might explode with a time delay of years to
billions of years. If the core degenerate scenario accounts for all SNe Ia,
then we calculate that about 0.2 per cent of the present WDs in the Galaxy are
massive. Furthermore, we find from the catalogs that the fraction of massive
WDs relative to all WDs is about 1-3 per cent, with large uncertainties.
Namely, five to ten times the required number. If there are many SNe Ia that
result from lower mass WDs, M_WD < 1.3Mo, for which another scenario is
responsible for, and the core degenerate scenario accounts only for the SNe Ia
that explode as massive WDs, then the ratio of observed massive WDs to required
is larger even. Our finding leaves the core degenerate scenario as a viable and
promising SN Ia scenario.
