Stellar Differential Rotation of F-stars using DI and ZDI: The case of HR1817

The measure of surface differential rotation via the motion of spots and/or magnetic features on the stellar surface is a critical part of understanding the stellar dynamo. Here we present several epochs of (Zeeman) Doppler imaging of the young late-F star HR1817 from 2001 until 2011. These results show that HR1817 exhibits a high shear of its surface features, significantly above the solar value. It would appear that F stars, with thin convective zones, have surface differential rotation rates much higher than that of low mass stars.