This series of radiation hydrodynamical calculations follows the collapse of one solar-mass molecular cloud cores all the way to the formation of the stellar core.The pre-stellar disc that is formed has a radius approaching 100 AU, and the end of one of the spiral arms manages to collect enough gas to form a self-gravitating fragment. All of this evolution occurs before the stellar core forms (which occurs at the end of the animation). This calculation was performed using 1 million SPH particles.
Source and further reading:
Simulation & visualisation by Matthew Bate, University of Exeter