Seismological studies of ZZ Ceti stars – II. Application to the ZZ Ceti class.

We used the detected pulsation modes and adiabatic pulsation models to do seismology of the class of ZZ Ceti stars and measure the H layer mass for 83 stars. We found the surface hydrogen layer to be within the range , with an average of , which is thinner than the predicted value of , indicating that the stars lose more mass during their evolution than previously expected. These results are preliminary and do not include the possible effects of realistic C/O profiles on the fits. [ABSTRACT FROM AUTHOR]