  EC13471-1258 is a detached eclipsing binary with Porb = 3h37m, comprising a
DA white dwarf and a dMe dwarf. Total eclipses of the white dwarf lasting 14
min, and a large amplitude ellipsoidal variation are seen in the light curve.
Flares from the dMe star occur regularly. Each star contributes roughly equal
amounts of light at 5500 Ang.
  HST STIS spectra show strong Ly alpha with weak metal lines, and yield Teff =
14220 K, log g = 8.34, Z = 1/30th solar, K = 138 km/s and V sin i = 400 km/s
for the white dwarf. Optical spectra yield the spectral type (M3.5-4.0), Teff =
3100 K, Z = solar, K = 266 km/s and V sin i = 140 km/s for the dMe star. The H
alpha emission line comprises 2 or more components and implies that very weak
mass transfer is occurring. The dynamical solution also implies that the dMe
star just fills its Roche lobe. Accurate masses and radii for each star were
derived: the dMe values favour the Clemens et al. (1998) mass-radius relation.
The large rotational velocity of the white dwarf (400 km/s) suggests that the
system has transferred mass in the past so that it is presently a hibernating
cataclysmic variable. The metallicity contrast between the component stars
provides an opportunity for tests of diffusion theory.
