  Resolution studies of test problems set baselines and help define minimum
resolution requirements, however, resolution studies must also be performed on
scientific simulations to determine the effect of resolution on the specific
scientific results. We perform a resolution study on the formation of a
protostar by modelling the collapse of gas through 14 orders of magnitude in
density. This is done using compressible radiative non-ideal
magnetohydrodynamics. Our suite consists of an ideal magnetohydrodynamics (MHD)
model and two non-ideal MHD models, and we test three resolutions for each
model. The resulting structure of the ideal MHD model is approximately
independent of resolution, although higher magnetic field strengths are
realised in higher resolution models. The non-ideal MHD models are more
dependent on resolution, specifically the magnetic field strength and
structure. Stronger magnetic fields are realised in higher resolution models,
and the evolution of detailed structures such as magnetic walls are only
resolved in our highest resolution simulation. In several of the non-ideal MHD
models, there is an off-set between the location of the maximum magnetic field
strength and the maximum density, which is often obscured or lost at lower
resolutions. Thus, understanding the effects of resolution on numerical star
formation is imperative for understanding the formation of a star.
