Submitting Campus

Daytona Beach


Physical Sciences

Document Type


Publication/Presentation Date



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.

Publication Title

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

Additional Information

Dr. von Hippel was not affiliated with Embry-Riddle Aeronautical University at the time this paper was published.