  We present an unbiased orbit solution and mass determination of the
components of the eclipsing binary NY Vir as a critical test for the formation
scenarios of subdwarf B stars. We obtained high-resolution time series VLT/UVES
spectra and high-speed multicolour VLT/ULTRACAM photometric observations of NY
Vir, a rapidly pulsating subdwarf B star in a short period eclipsing binary.
Combining the radial velocity curve obtained from the VLT/UVES spectra with the
VLT/ULTRACAM multicolour lightcurves, we determined numerical orbital solutions
for this eclipsing binary. Due to the large number of free parameters and their
strong correlations, no unique solution could be found, only families of
solutions. We present three solutions of equal statistical significance, two of
which are compatible with the primary having gone through a core He-flash and a
common-envelope phase described by the $\alpha$-formalism. These two models
have an sdB primary of 0.466 \msol and 0.389 \msol, respectively. Finally, we
report the detection of the Rossiter-McLaughlin effect for NY Vir.
