Cool Stars 14 - Submitted Abstract # 294
This version created on 05 October 2006

The Search for Magnetic White Dwarfs in Cataclysmic Variable
Progenitor Systems


Nicole M. Silvestri, University of Washington
Mara. P. Lemagie, University of Washington
Suzanne L. Hawley, University of Washington
Gary D. Schmidt, University of Arizona and Steward Observatory
James Liebert, University of Arizona and Steward Observatory
Paula Szkody, University of Washington
Lee Mannikko, University of Washington
Michael A. Wolfe, University of Washington

We present the latest catalog of more than 1200  spectroscopically
selected close binary systems observed with the Sloan Digital Sky
Survey through the now public Data Release Five (Adelman-McCarthy et
al.  2006).  We use the catalog to search for magnetic white dwarfs
(MWD) in cataclysmic variable (CV) progenitor systems.  Given that
~25% of CVs contain a MWD (eg.  Polars, Intermediate-Polars) it is
quite surprising that we find only two, low signal-to-noise ratio (<
5) MWDs candidates.  Both of the candidate MWDs have relatively low
measured field strengths (< 10  MG) which are similar to those of
Intermediate-Polars but are much less than the average field strength
of the current Polar population.  Follow-up observations of these two
systems are required to definitively cast the WDs as magnetic.  Even
if these two pairs prove to be the first evidence of MWD + M dwarf
binaries, there is still a large disparity between the number in close
binary progenitor systems and in the CV population.  

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