Speaker
Dr
Thomas Hackmann
Description
We present surface (Doppler) imaging temperature maps of the
FK Comae-type star HD 199178 (V1794 Cyg). The maps have been
calculated from high resolution spectra and simultaneous
Johnson V-photometry obtained between 1994 and 1997. All
maps reveal a high latitude spot, which is 1200-1600 K
cooler than the mean surface temperature. The observed
slightly flat bottomed absorption lines can be explained by
antisolar surface differential rotation. The presence of
differential rotation is supported by the variations in the
photometric rotation period.
