Doppler imaging of stellar surface structure

We present the first Doppler image of a solar-type G dwarf in the Pleiades open cluster. As such, the star represents the Sun at an age of approximately 100 Myr and could be an important target for further progress in magnetic-braking and angular-momentum-transport theories. Our image reconstructions were done from a full spectrum inversion with a total of 38 spectral lines but we also present single-line inversions using the prominent Li i 6707-Å line and the nearby Ca i 6717-Å line. The maps reveal cool spots at or near the pole and within the equatorial regions, in contradiction to our predictions from flux-tube modelling that only medium-latitude spots should be seen. The maps also show several warm spots near the equatorial regions but their reality needs to be confirmed. A polar spot is recovered but likely consists of several smaller spots at very high latitudes touching the visible pole instead of a big cap-like spot as seen on some RS CVn binaries.