High-frequency stellar oscillations. XIII. Observations of apparently quiescent white dwarfs

Thirty-four time-series photomertic observations of 17 spectroscopically confirmed white dwarfs observed during a search for new southern white-dwarf variable (ZZ Ceti stars) are summarized; all stars examined are apparently nonvariable on time scales of 4 s to 20--30 minutes. A list and a two-color diagram of white dwarfs and suspected white dwarfs examined for high-frequency variability in various surveys are also provided. It is pointed out that several sets of conflicting observations may be indicative of variability on time scales for which observational data are largely lacking, i.e., greater than approx.30 minutes