Blue edge of the ZZ Ceti instability strip versus mass

In this work we test the theoretical results derived from pulsation models in which the blue edge temperature of the ZZ Ceti instability strip depends on the stellar mass. By using the fundamental parameters (T-eff and M) and the results of the time series photometry of a sample of DA stars, we found all the ZZ Ceti stars in our sample but one (G 226-29) fall inside the instability strip if the theoretical blue edge is shifted by 300 K to higher temperature. Our biggest sources of uncertainty are in the T-eff and M determinations, but by assuming that the relative ordering in the temperature among the ZZ Ceti stars is reliable, we conclude that the instability strip boundaries depend on stellar mass.