| Autor: |
Usenko, I. A., Kovtyukh, V. V., Klochkova, V. G., Panchuk, V. E., Yermakov, S. V., Usenko, I. A., Kovtyukh, V. V., Klochkova, V. G., Panchuk, V. E., Yermakov, S. V. |
| Zdroj: |
Astronomy and Astrophysics; March 2001, Vol. 367 Issue: 3 p831-839, 9p |
| Abstrakt: |
The small-amplitude Cepheid SU Casand four members of the association Cas OB2(HD 16893, HD 17327a and b, HD 17443) were investigated, using high-resolution CCD spectra. The following results were obtained: 1) All these objects have the same metallicity values, close to that of the Sun; 2) Elemental abundance indicates that SU Casis a post first dredge-up star with an age from 1 108to 1.45 108yr, and it is not crossing the Cepheid instability strip for the first time. The mean value of $\log g$= 2.35 corresponds to pulsations in the fundamental tone, although errors in gravity estimations provide overtone pulsations. The questions about its pulsational mode and membership in Cas OB2remained open; 3) HD 17327ais a slowly rotating HgMn-star with the highest helium content among such objects, while HD 16893also has a manganese overabundance and might be classified as an Am-star; 4) HD 17327band HD 17443are rapidly rotating main-sequence stars, while HD 17443has a helium content comparable with that of the Sun. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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