The appearance of magnetic flux on the surfaces of the early main-sequence F stars

Available chromospheric, transition region, and coronal observations of the early main-sequence F stars are examined in order to find that while these objects exhibit enhanced levels of magnetic field-related radiative emissions, significant inhomogeneities in surface activity are not present. This phenomenon is discussed within the context of the calculations published by Schmitt and Rosner (1983) for the production of flux ropes of various spatial scales at a given rotation rate at the bottom of a stellar convection zone. It is found that the spatial scales and area contrast of emergent magnetic flux in these stars that, as a class, are characterized by rapid rotation and thin convection zones are substantially reduced relative to that of the sun.