Pulsating or not? A search for hidden pulsations below the red edge of the ZZ Ceti instability strip
The location of the red edge of the ZZ Ceti instability strip is definedobservationally as being the lowest temperature for which a white dwarfwith a H-rich atmosphere (DA) is known to exhibit periodic brightnessvariations. Whether this cut-off in flux variations is actually due to acessation of pulsation or merely due to the attenuation of anyvariations by the convection zone, rendering them invi