| Research Abstract |
(1) High resolution ultraviolet spsectroscopic data of early type stars including CP stars are analyzed quantitatively. They were obtained with the IUE and Copernicus satellites. Resonance lines of Ga II and Ga III in B-type CP stars were analyzed and anomalous abundances of Ga were found not only in Hg-Mn stars but also in magnetic (Si type) stars (M. Takada-Hidai, K. Sadakane, and J. Jugaku, 1986, Ap. J., 304, 425). The resonance line of Zn II at 2062 A in Hg-Mn stars was analyzed using the spectrum synthsis method. A remarkable variation in the abundance of Zn was found among Hg-Mn stars (K. Sadakane, J. Jugaku, and M. Takada-Hidai, 1988, Ap. J., 325, 776). The resonance line of Hg II at 1942 A in Sirius and Vega was analyzed and Hg in Vega was found to be under-abundant with respect to the solar system abundance (K. Sadakane, J. Jugaku, and M. Takada-Hidai, 1988, P. A. S. P., 100, 811).
(2) High S/N ratio spectra of 12 A-type stars in the 8700 A region were obtained using a CCD detector at the Okayama Astrophysical Observatory. Absorption lines of N I and S I were analyzed for their abundances in these 12 stars using model atmospheres. Abundances of both N and S are found to be normal in most stars while they both are underabundat in the two CP stars (73 DMa and UMa). Details will be published shortly (K. Sadakane and M.Okyudo, 1989, submitted to P. A. S. Japan).
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