Top: nightly Strömgren Δ y magnitudes from the T10 APT for the 2001–2002 observing season. Middle: frequency spectrum of the Δ y observations showing the best-fit period of 8.49 days, which we take to be the rotation period of the active component(s). Bottom: Δ y observations phased with the 8.49 day rotation period have an amplitude of 0.008 mag. The horizontal dashed lines in the top and bottom panels represent the mean brightness of the Δ y data set.