Do tidal effects determine the spot distribution on active binaries?

Observations of spot distributions on active binaries indicate the existence of preferred longitudes, which are more pronounced if the system period is shorter. This suggests that this effect is caused by the proximity of the companion star. We explore whether preferred longitudes can be explained by tidal effects on the dynamics of magnetic flux tubes, which are thought to give rise to starspots upon emergence at the stellar surface. We find that in the case of fast-rotating binaries flux tubes erupting at mid latitudes show indeed a considerably non-uniform longitudinal distribution.