Below I illustrate typical line profile variation produced by different types of structures on the surfaces of rotating stars. I am doing Doppler Imaging analysis of all these different types of starspots.
|Temperature||Chemical abundance||Magnetic field||Non-radial pulsation|
|Temperature spots Active late-type stars have cool, dark spots on their surfaces. Their contribution to the disk-averaged spectrum is smaller than for the unspotted part of the stellar surface. Thus, the signature of cool spot is a bump travelling from blue to red across the stellar spectral line.|