However, when two clouds or clumps collide off-centre, introducing some rotational motion to the system, the simulations show that multiple protostar systems can be formed, in accordance with observations. Magnetic fields are observed in star-forming regions, and researchers involved in star formation are divided over the importance of magnetic fields in this context. A considerable amount of work has been done on the effects of magnetic fields on the latest stages of star formation, after the protostellar disk has formed. The effect of the magnetic field has also been considered in the slow collapse of single clouds. However, little is known of the influence of magnetic fields on the early stages of violent collapse such as that initiated by cloud collisions or compression by supernova shocks.
Magnetic fields help support molecular clouds against collapse.
Analytic work on shock structure by Sue Byleveld, Don Melrose and Helen Pongracic, suggests that although it is more difficult to achieve the high compression necessary for star formation when a magnetic field is present, it is still possible. Sue Byleveld is generalizing the 3D hydrodynamical code originally developed at Cardiff to include the effects of magnetic fields. The new code will be used to determine the extent to which the magnetic field influences the collapse leading to star formation. The molecular clouds in Orion are observed to be regions of prolific star formation. Helen and collaborators from the University of Iowa hope to determine the origin of these bullets by modelling them as explosive events.