The unique magnetic cataclysmic variable V1432 Aql - Third type of minima and synchronization

Results of a CCD study of the variability of the unique magnetic cataclysmic variable V1432 Aql from the Astronomical Observatory of Mallorca are presented. The "multi-comparison star" method had been applied for better accuracy estimates. The linear ephemeris based on 76 timings of orbital eclipses for 1993-2004 is HJD(min) = 2451 492.09876(14) + 0.140235812(12) + E. For the wide minima due to the spin variability, the quadratic ephemeris HJD(spin) = 2 449 638.327427(74) + 0.14062831(23). E-7.81(11) x 10(-10) E-2 was determined. The rate of the spin-up of the white dwarf corresponds to the synchronization time-scale determined to be (96.7 +/- 1.5) years, in an agreement with theoretical model of the accretion torque. A third type of minima was detected that occur with the spin period. It was interpreted as indicating presence of the second accretion column. For adopted values of mass M-1 = 0.9 M circle dot and M-2 = 0.3 M circle dot, the estimated accretion rate is similar to 7 x 10(-10) M circle dot/yr. Further multi-colour monitoring is needed to study of late stages of the "spin-orbital" synchronization and periodic changes of the accretion geometry caused by "idling" of the white dwarf.