DOPPLER IMAGING OF SPOTTED STARS : APPLICATION TO THE RS CANUM VENATICORUM STAR HR 1099.

A technique for imaging the surfaces of certain rapidly rotating spotted stars is discussed. The method exploits the correspondence between wavelength position across a rotationally broadened spectral line and spatial position across the stellar disk. Preliminary Doppler Images of the RS CVn star HR 1099 show spots which exhibit a striking similarity in shape and location to X ray images of solar coronal holes. It is suggested that the large star spots on RS CVn's and other active late-type stars emerge at low latitude as scaled-up analogs of solar complexes, but as they migrate poleward, they more closely resemble photospheric analogs of solar coronal holes. The evolution of starspots appears remarkably similar to that of large-scale magnetic fields of the sun.