Though widely spread across the H-R diagram the compact pulsators have much in common. All are multi-periodic, and most have extremely complex light curves. All appear to be pulsating in nonradial g-modes, with temperature variations responsible for the bulk of the light modulations. The g-modes are global in nature and, typically, many are excited in each pulsator, so they are a rich source of seismological information about the interior regions of the white dwarf stars.
The pulsating DB white dwarf stars (DBV’s) form one of the three distinct classes of pulsating compact objects currently known. We find these classes nearly uniformly distributed in log Te
spanning virtually the whole range of the white dwarf cooling sequence, from the hot DOV stars at log Te
~ 5 to the DAV (ZZ Ceti) stars at log Te
~ 4; the DBV stars, with logTe
~ 4.5, fall in the middle.