Different stars can exhibit very different levels of activity. The Sun’s coronal mass ejections, flares and sunspots – all signs of solar activity – are rather feeble on an astronomical scale. Other stars are up to ten times more active, for example sporting huge starspots that cover a large portion of their disc. While researchers have long identified the magnetic fields generated in the interior of stars in a dynamo process as drivers of activity, the exact workings of this dynamo are still unclear. A group of scientists led by the Max Planck Institute for Solar System Research (MPS) in Germany has now searched for an answer by applying the same analysis to a sample of both main sequence and more evolved stars. They find that a common, turbulence-dependent dynamo mechanism plays a crucial role for stellar activity in all stages of stellar evolution. The results are published in next week’s issue of Nature Astronomy. Read the full press release here .