Post common envelope binaries from the SDSS. VI. SDSS
  J120615.73+510047.0: a new low accretion rate magnetic binary
  We report the discovery of the ninth pre-polar, consisting of a late-type
ZAMS secondary and a magnetic white dwarf. The white dwarf accretes at extreme
low rate, dot{M} ~ 10**-14 Msun/yr, from the wind of the companion donor star.
The source was found in our systematic search for WD/MS binaries within
SDSS/SEGUE. Based on seven Sloan-spectra we estimate a binary period of ~200,
230, or 270 min. The UV to IR spectral energy distribution was decomposed into
a dM3-dM4 ZAMS secondary and a cool white dwarf, ~9000 K, which consistently
imply a distance between 360 and 420 pc. The optical spectrum displays one
pronounced cyclotron hump, likely originating from a low-temperature plasma, ~1
keV, in a field of 108 MG. We comment on the evolutionary link between polars
and pre-polars.
