| タイトル | Two-phase ultraviolet spectrophotometry of the pulsating white dwarf ZZ Piscium |
| 著者（英） | Holm, A. V.; Panek, R. J.; Kemper, E.; Grauer, A. D.; Schiffer, F. H., III; Bond, H. E. |
| 著者所属（英） | Louisiana State Univ.|Arkansas Univ. |
| 発行日 | 1985-02-15 |
| 言語 | eng |
| 内容記述 | Spectra of the pulsating white dwarf ZZ Psc (= G29-38) were obtained using the International Ultraviolet Explorer. By using a multiple-exposure technique in conjunction with simultaneous ground-based exposure-metering photometry, it was possible to obtain mean on-pulse and off-pulse spectra in the 1950-1310 A wavelength range. The ratio of the time-averaged on-pulse to off-pulse spectra is best fitted by a temperature variation that is in phase with the optical light variation. This result is consistent with the hypothesis that the observed variation is due to a high-order nonradial pulsation. Conventional ultraviolet spectra of ZZ Psc showed broad absorption features at 1390 and 1600 A. These features are also found in the spectra of the cool DA-type white dwarfs G226-29 and G67-23, and appear to increase in strength with decreasing temperature. A possible explanation for the 1600 A feature is absorption by the satellite band of resonance-broadened hydrogen Ly-alpha. Such absorption would also help explain a discrepancy between the observed pulsation amplitude shortward of 1650 A and the predicted amplitudes based on model atmospheres. |
| NASA分類 | ASTROPHYSICS |
| レポートNO | 85A27013 |
| 権利 | Copyright |
| URI | https://repository.exst.jaxa.jp/dspace/handle/a-is/392485 |
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