  The distance to the Orion Nebula Cluster (ONC) is estimated using the
rotational properties of its low-mass pre main-sequence (PMS) stars. Rotation
periods, projected equatorial velocities and distance-dependent radius
estimates are used to form an observational sin i distribution (where i is the
axial inclination), which is modelled to obtain the distance estimate. A
distance of 440+/-34 pc is found from a sample of 74 PMS stars with spectral
types between G6 and M2, but this falls to 392+/-32 pc when PMS stars with
accretion discs are excluded on the basis of their near-infrared excess. Since
the radii of accreting stars are more uncertain and probably systematically
underestimated, then this closer distance is preferred. The quoted
uncertainties include statistical errors and uncertainties due to a number of
systematic effects including binarity and inclination bias. This method is
geometric and independent of stellar evolution models, though does rely on the
assumption of random axial orientations and the Cohen & Kuhi (1979) effective
temperature scale for PMS stars. The new distance is consistent with, although
lower and more precise, than most previous ONC distance estimates. A closer ONC
distance implies smaller luminosities and an increased age based on the
positions of PMS stars in the Hertzsprung-Russell diagram.
