Results are presented from the first detailed spectroscopic observations of the recently identified intermediate polar RXJ0028.8+5917/V709 Cas .
The study of the emission line radial velocities allows us to remove the uncertainties on the different aliases of the orbital period and a best value is found at ( 0.2225 \pm 0.0002 ) day .
It is also found that the system shows significant EW \sim ( 2-4 ) Å broad absorptions affecting the Balmer lines from H _ { \delta } to H _ { \beta } .
These broad absorptions are interpreted as the contribution of an underlying white dwarf atmosphere .
The characteristics of the absorptions are found to be consistent with a DA log g = 8 white dwarf at a temperature of \sim 23 000 K , contributing \sim 17 % ( at 4500 Å ) to the overall flux .
This is the first direct detection of a white dwarf in an intermediate polar system .
The absence of significant Zeeman splitting indicates a magnetic field lower than 10 MG , confirming that , at least in some cases , intermediate polars have weaker fields than polars .
Different possibilities are discussed to explain the substantial contribution of the white dwarf to the overall flux .