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|
|Chemical abundance spots Hot stars often posses inhomogeneous distribution of chemical elements across their surfaces. The lines of spotted elements show large variation during rotation of the star. Typically, elements have an enhanced concentration inside spots and normal abundance outside. The resulting spectral line variation is seen as dips in the line profile, propagating from blue to red.|