The magnetic field of a star is generated within regions of the interior where convective circulation occurs . This movement of conductive plasma functions like a dynamo , wherein the movement of elecrical charges induce magnetic fields , as does a mechanical dynamo . Those magnetic fields have a great range that extend throughout and beyond the star . The strength of the magnetic field varies with the mass and composition of the star , and the amount of magnetic surface activity depends upon the star 's rate of rotation . This surface activity produces starspots , which are regions of strong magnetic fields and lower than normal surface temperatures . Coronal loops are arching magnetic field flux lines that rise from a star 's surface into the star 's outer atmosphere , its corona . The coronal loops can be seen due to the plasma they conduct along their length . Stellar flares are bursts of high @-@ energy particles that are emitted due to the same magnetic activity .