Hua-Bai Li and his colleagues measured magnetic fields in the Orion molecular cloud region, which includes the famous Orion Nebula.
The background image shows the far-infrared map in representative color and logarithmic scale. Superposed on it are the magnetic field directions inferred from optical polarimetry data (blue lines) tracing the diffused regions. The average of all the optical data is shown as the thick gray line. Magnetic fields within eight high-density cloud cores (labels A
through H on the background map) are mapped using submillimeter polarimetry and the results are shown as insets, using red lines on individual representative-color intensity maps. The average direction of each core is shown as a white line superposed on the core map; these white lines also are plotted on the background map. Even though the core separations exceed the core sizes by as much as a factor of 100, they are for the most part "magnetically connected," i.e. the cores' average field directions are similar. Moreover, these directions are close to the average field direction seen in the diffused regions.