HD 74308

Observations and a new interpretation for the Delta Scuti variable star VZ CANCRI The pulsation characteristics of VZ Cnc were examined, together with thepossibility of He settling in the stellar envelope. Data were gatheredwith the 40 cm Tortugas telescope and photometry system and includedcomparison figures in UBV for HD 73938 and HD 74308. The observationswere made in February-April 1983 and were subjected to Fouriertransforms and least squares analysis. Light variations in VZ Cnc wereattributed to coupling between two frequencies, a condition whichproduced higher amplitudes than either component alone. A stable periodratio of 0.80 was calculated, with the main pulsational energyconcentrated in the first frequency, 5.6 cycles/day. The secondfrequency exhibited 7.0 cycles/day. The period ratio supports a Hedepletion process. A stellar temperature of 7500 K would eliminate thenecessity of He settling as part of the model and confirm the presenceof 1H and 2H, rather than fundamental, pulsation modes.
Photometric behavior of magnetic stars Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1968ApJ...154..945S&db_key=AST
The Cluster-Type Variable VZ CANCRI. Abstract image available at:http://adsabs.harvard.edu/cgi-bin/nph-bib_query?1955ApJ...121..690F&db_key=AST

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