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The magnetic fields, activity and dynamos of young solar-type stars can beempirically studied using time-series of spectropolarimetric observations andtomographic imaging techniques such as Doppler imaging and Zeeman Dopplerimaging. In this paper we use these techniques to study the young Sun-like starEK Draconis (Sp-Type: G1.5V, HD 129333) using ESPaDOnS at theCanada-France-Hawaii Telescope and NARVAL at the T\`elescope Bernard Lyot. Thismulti-epoch study runs from late 2006 until early 2012. We measure high levelsof chromospheric activity indicating an active, and varying, chromosphere.Surface brightness features were constructed for all available epochs. The2006/7 and 2008 data show large spot features appearing atintermediate-latitudes. However, the 2012 data indicate a distinctive polarspot. We observe a strong, almost unipolar, azimuthal field during all epochsthat is similar to that observed on other Sun-like stars. Using magneticfeatures, we determined an average equatorial rotational velocity, \Omega_eq,of 2.50 +/- 0.08 rad/d. High levels of surface differential rotation weremeasured with an average rotational shear, \Delta\Omega, of 0.27 +0.24-0.26rad/d. During an intensively observed 3-month period from December 2006 untilFebruary 2007, the magnetic field went from predominantly toroidal ( approx.80%) to a more balanced poloidal-toroidal (approx. 40-60%) field. Although thelarge-scale magnetic field evolved over the epochs of our observations, nopolarity reversals were found in our data.

Magnetic fields on young, moderately rotating Sun-like stars II. EK Draconis (HD 129333)