We use the new ZZ Ceti stars (hydrogen atmosphere white dwarf variables; DAVs) discovered within the Sloan Digital Sky Survey (Mukadam et al. 2004) to re-define the empirical ZZ Ceti instability strip. This is the first time since the discovery of white dwarf variables in 1968 that we have a homogeneous set of spectra acquired using the same instrument on the same telescope, and with con- sistent data reductions, for a statistically significant sample of ZZ Ceti stars. The homogeneity of the spectra reduces the scatter in the spectroscopic temperatures and we find a narrow instability strip of width ∼ 950K, from 10850–11800K. We question the purity of the DAV instability strip as we find several non-variables within. We present our best fit for the red edge and our constraint for the blue edge of the instability strip, determined using a statistical approach.
The Astrophysical Journal
The American Astronomical Society, The Institute of Physics
Grant or Award Name
Texas Advanced Research Program grant ARP-0543 and NASA grant NAG5- 13094
Scholarly Commons Citation
Mukadam, A. S., von Hippel, T., Winget,, D. E., & Montgomery, M. H. (2004). Re-defining the Empirical ZZ Ceti Instability Strip. The Astrophysical Journal, 612(2). https://doi.org/10.1086/422551