The Identification of Pulsation Modes of High‐Amplitude δ Scuti Stars in ω Centauri and the Carina Galaxy
| Autor: | D. H. Mcnamara |
|---|---|
| Rok vydání: | 2000 |
| Předmět: | |
| Zdroj: | Publications of the Astronomical Society of the Pacific. 112:1096-1102 |
| ISSN: | 1538-3873 0004-6280 |
| DOI: | 10.1086/316605 |
| Popis: | We analyze photometric observations of high-amplitude d Scuti stars (HADS) in the globu- lar cluster u Cen and the Carina galaxy. The pulsation modes of the HADS are inferred primarily from their positions in V ,l ogP diagrams. For u Cen we identify nine fundamental pulsators (F), 22 Ðrst-overtone (1, O), one second-overtone (2, O), and probably two third-overtone (3, O) stars. The majority of the F pulsators have light amplitudes *V o 0.15 mag, but two have *V \ 0.15 mag. Four of the 1, O pulsators have *V ( 0.15 mag, but the majority have smaller amplitudes. We Ðnd that the F pulsators tend to have more asymmetric light curves. The Carina variables are all large-amplitude variables. Fourteen are F pulsators and six are 1, O pulsators. At least one and possibly two 1, O stars appear to have asymmetric light curves unlike those found in u Cen. The data are very uncertain, so the asymmetry may be an artifact of observational uncertainty. The HADS data along with their P-L relation are utilized to Ðnd the distances to u Cen and the Carina galaxy and absolute magnitudes of their horizontal branches (HB) or RR Lyrae stars. We Ðnd the distances to be d \ 6370 pc to u Cen and d \ 124,000 pc to the Carina galaxy. The for the u Cen RR |
| Databáze: | OpenAIRE |
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