Folded radial velocities for δ Cephei, using an epoch of 2443674.144 days and period of 5.366316 days. The data were fitted with an 8th order Fourier expansion, shown by the solid curve. Data from Bersier et al. (1994) needed to be shifted slightly to minimize the scatter in the combined radial velocity curve. Error bars are omitted for clarity. (See online edition for a color version.)