Doppler images from dual-site observations of southern rapidly rotating stars - I. Differential rotation on PZ Tel

Abstract

We present Doppler images of the young, late-type star PZ Tel from spectroscopic observations at two epochs. The 0.95-d period necessitated dual-site observations in order to obtain full phase coverage. The resulting maximum entropy reconstructions based on least-squares deconvolved profiles derived from similar to 2800 photospheric absorption lines reveal the presence of starspots at ail latitudes. By cross-correlation of constant-latitude strips from the images, we derive a measure of rotation as a function of latitude. The rate of surface shear is found to be in close agreement with the solar value. Ha absorption transients reveal several prominences to be present at the time of observation. We also examine further evidence for the young evolutionary status of PZ Tel through radial velocity, and lithium abundance.