Observations and a new interpretation for the delta Scuti variable star VZ Cancri.

The pulsation characteristics of VZ Cnc were examined, together with the possibility of He settling in the stellar envelope. Data were gathered with the 40 cm Tortugas telescope and photometry system and included comparison figures in UBV for HD 73938 and HD 74308. The observations were made in February-April 1983 and were subjected to Fourier transforms and least squares analysis. Light variations in VZ Cnc were attributed to coupling between two frequencies, a condition which produced higher amplitudes than either component alone. A stable period ratio of 0.80 was calculated, with the main pulsational energy concentrated in the first frequency, 5.6 cycles/day. The second frequency exhibited 7.0 cycles/day. The period ratio supports a He depletion process. A stellar temperature of 7500 K would eliminate the necessity of He settling as part of the model and confirm the presence of 1H and 2H, rather than fundamental, pulsation modes.