2008ApJ...677L.113S

We have discovered a partially eclipsing white dwarf, low-mass M dwarf binary (3.015114 hr orbital period), SDSS J143547.87+373338.5, from 2007 May observations at the WIYN telescope. Here we present blue-band photometry of three eclipses. Eclipse fitting gives main-sequence solutions to the M dwarf companion of M_S=0.15-0.35 M_☉ and R_S=0.17-0.32 R_☉. Analysis of the SDSS spectrum constrains the M dwarf further to be of type M4-M6 with M_S=0.11-0.20 M_☉. Once full radial velocity curves are measured, high-precision determinations of the masses and radii of both components will be easily obtained without any knowledge of stellar structure or evolution. ZZ Ceti pulsations from the white dwarf were not found at our 4 mmag detection limit.