Journal of The Korean Astronomical Society (천문학회지)
- Volume 26 Issue 2
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- Pages.115-134
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- 1993
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- 1225-4614(pISSN)
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- 2288-890X(eISSN)
PULSATIONAL CHARACTERISTICS OF V1719 CYGNI WITH PECULIAR LIGHT CURVE
- KIM CHULHEE (Department of Earth Science Education, Chonbuk National University) ;
- KIM SEUNG-LI (Department of Astronomy, Seoul National University) ;
- SADAKANE KOZO (Astronomical Institute, Osaka Kyoiku University)
- Published : 1993.10.01
Abstract
The light curve and radial velocity curve of multiperiodic dwarf cepheid VI719 Cyg (HD200925) with peculiar light curve have been reanalyzed in order to identify the oscillation modes to confirm the helium settling within the envelope. To do these, through the period search for the photometric and radial velocity data from the literature, two different periods were determined and the oscillation modes corresponding to the first and second periods were identified as the fundamental and first radial overtones. Hence the helium settling within the envelope was confirmed from the period ratio. The color excess, metallicity, effective temperature, and surface gravity corresponding to two different modes were determined and it was found that these parameters almost do not depend upon different oscillation mode. By utilizing the surface brightness method, we investigated the variation of angular diameter and radial displacement and it was found that the angular variation is very peculiar. Also by referring to the stellar models, mass and age were determined as