Fig. 2a and b. Left: Periodogram from the 1994-1995 V -band APT data. Right: Light and color curves phased with and the ephemeris in Eq.(1). The upper left panel shows the window function for the APT data with strong aliasing towards multiples of one day. The largest reduction of the residuals is achieved with a period near the orbital period at 8.232 0.003 days (frequency ). The other indicated frequencies are just aliases of the true frequency. The right panels show the light and color curves phased with . Despite that these plots show all combined data from 1994 we see a clear asymmetry in the light curve as well as in the color curve with a maximum at around phase 0.2 and a minimum at around 0.8.