Negative Superhumps and Red Noise in the Cataclysmic Binary TT Arietis: the International Campaign "tt ARI-94"

Results obtained during the international observational campaign "TT Ari-94" are briefly discussed. During 258 hours, totally 51299 observations were obtained in 12 observatories. The moments of 68 individual maxima and 74 minima are tabulated. The linear ephemeris for the maximum is MaxHJD=2449645.4255+/-0.0003 deg +(0.133160 +/- 0.000004 deg)ṡ E for our data obtained in JD 2 449 614-690. The period value is distinctly outside the interval 0.1326-0.13298 deg obtained for previous years. It still corresponds to the 'negative superhump' state, whereas for a normal 'positive superhump' the value predicted by Tremko et al. (1996, As.Ap. 312, 121) is P=0.1426+/-0.00006 deg. The data prewhitened in respect to the superhump variations show the red noise power-law power spectrum with an index gamma=1.3...2.6.