Doppler Images of Spotted Late-Type Stars

Doppler imaging is a technique for deriving resolved images of rapidly rotating stars from a detailed analysis of very high signal-to-noise high resolution spectral line profiles. An improved version of this technique is presented, which now uses principles of maximum entropy image reconstruction to invert the line profile information. The effects that noise, finite resolution, and uncertainties in the assumed stellar physics have on the resultant images were explored through various test simulations. Doppler images of two spotted late-type stars, the RS CVn-type star HR 1099, and the FK Com-type star HD 199178, are presented and discussed.