TECHNIQUES FOR SURFACE IMAGING OF STARS

Surface imaging of stars from the profiles of spectral lines has becom e an important tool in modem astrophysics. It is presently used for ma pping the distribution of chemical elements on Ap stars and the variat ion in temperature over the surface of late-type stars. Magnetic-field maps will be produced as soon as high-quality polarization observatio ns are available. Recently imaging techniques have been developed for application to eclipsing binary stars. In this paper we review the imp rovements we have found to result in more reliable and detailed maps i n all aspects of surface imaging.