We present interferometric observations of the \sigma Orionis triple system using the CHARA Array , NPOI , and VLTI .
Using these measurements , we spatially resolve the orbit of the close spectroscopic binary ( Aa , Ab ) for the first time and present a revised orbit for the wide pair ( A , B ) .
Combining the visual orbits with previously published radial velocity measurements and new radial velocities measured at CTIO , we derive dynamical masses for the three massive stars in the system of M _ { Aa } = 16.99 \pm 0.20 M _ { \odot } , M _ { Ab } = 12.81 \pm 0.18 M _ { \odot } , and M _ { B } = 11.5 \pm 1.2 M _ { \odot } .
The inner and outer orbits in the triple are not coplanar , with a relative inclination of 120 ^ { \circ } –127 ^ { \circ } .
The orbital parallax provides a precise distance of 387.5 \pm 1.3 pc to the system .
This is a significant improvement over previous estimates of the distance to the young \sigma Orionis cluster .