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arXiv · 1709.10200

Asteroseismology of the ultramassive ZZ Ceti star WD 0246+326

Chun Li·Jianning Fu·Lester Fox-Machado·Jie Su·Fangfang Chen
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Abstract

The internal structures of pulsating white dwarfs can be explored only with asteroseismology. Time series photometric observations were made for the pulsating DA white dwarf (ZZ Ceti star) WD~0246+326 during 9 nights in 2014 with a bi-site observation campaign. Eleven frequencies were detected including 1 triplet, 2 doublets, and 4 single modes, which are identified as either $l=1$ or $l=2$ modes with the complementarity of frequencies present in the literature. From the multiplets, the rotation period of \astrobj{WD~0246+326} is derived as $3.78\pm 0.11$ days. The average period spacing of the l=1 modes $ΔP=29.3\pm 0.2s$, implies that \astrobj{WD~0246+326} may be a massive ZZ Ceti star concerning the $ΔP-M_*$ relationship for the DAVs. Preliminary analysis derives the stellar parameters of $M_*=0.98\pm0.01$~${\rm M_\odot}$ and $T_{\rm eff}=11700\pm100$~K by fitting the theoretical frequencies of the eigen modes to the observed ones.

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Chun Li, Jianning Fu, Lester Fox-Machado, Jie Su, Fangfang Chen. 2017-09-28. Asteroseismology of the ultramassive ZZ Ceti star WD 0246+326. https://doi.org/10.1016/j.newast.2017.03.003

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