Characterizing the pulsations of the ZZ Ceti star KUV 02464+3239 |
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| Authors: | Zs Bognár M Paparó P A Bradley A Bischoff-Kim |
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| Institution: | Konkoly Observatory of the Hungarian Academy of Sciences, PO Box 67., H-1525 Budapest, Hungary;X-4, MS T-087, Los Alamos National Laboratory, Los Alamos, NM 87545, USA;Department of Chemistry, Physics and Astronomy, Georgia College &State University, CBX 82, Milledgeville, GA 31061, USA |
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| Abstract: | We present the results on period search and modelling of the cool DAV star KUV 02464+3239. Our observations resolved the multiperiodic pulsational behaviour of the star. In agreement with its position near the red edge of the DAV instability strip, it shows large amplitude, long-period pulsation modes, and has a strongly non-sinusoidal light curve. We determined six frequencies as normal modes and revealed remarkable short-term amplitude variations. A rigorous test was performed for the possible source of amplitude variation: beating of modes, effect of noise, unresolved frequencies or rotational triplets. Among the best-fitting models resulting from a grid search, we selected three that gave l = 1 solutions for the largest amplitude modes. These models had masses of 0.645, 0.650 and 0.680 M ⊙ . The three 'favoured' models have M H between 2.5 × 10?5 and 6.3 × 10?6 M * and give 14.2–14.8 mas seismological parallax. The 0.645 M ⊙ (11 400 K) model also matches the spectroscopic log g and T eff within 1σ. We investigated the possibility of mode trapping and concluded that while it can explain high amplitude modes, it is not required. |
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| Keywords: | techniques: photometric stars: individual: KUV 02464+3239 stars: oscillations white dwarfs |
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