TWISTING MAGNETIC-FIELDS IN THE CORE REGION OF OMC-1

We present results of imaging polarimetry of the H-2 upsilon = 1-0 S(1 ) line in the core region of OMC-1. The polarization vectors are produ ced by dichroic absorption in a medium of aligned grains and therefore follow the direction of the magnetic field in the region. The magneti c field strength estimated from the dispersion of polarization vectors is approximately 10 mG, which is sufficient to align the grains via t he Davis-Greenstein mechanism. The presence of a twist in the directio n of the magnetic field about the self-luminous object IRc2 is clearly seen. We propose a model which requires the magnetic field to be polo idal outside the disc of IRc2, but which develops a significant transv erse component close to the disc.