WD J004917.14−252556.81: the most massive pulsating white dwarf
WD J004917.14−252556.81: the most massive pulsating white dwarf
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WD J004917.14â252556.81：最大质量的脉动白矮星
DOI：
10.1093/mnras/stad1113
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发表时间：
2023
影响因子：
4.8
通讯作者：
Althaus, Leandro G.
中科院分区：
文献类型：
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作者：
Kilic, Mukremin;Córsico, Alejandro H.;Moss, Adam G.;Jewett, Gracyn;De Gerónimo, Francisco C.;Althaus, Leandro G.
本文介绍了阿帕奇点天文台（APO）和双子座天文台对WD J 004917.14 - 252556.81的测光结果。WD J 004917.14 - 252556.81是一颗K和logg = 9.34的超大质量DA白色矮星。我们在两个显著的频率上探测到了变化，使J0049 − 2525成为目前已知的最大质量的脉动白色矮星，其M = 1.31 M（对于CO核心）或1.26 M（对于ONe核心）。J0049 − 2525没有任何双星合并的迹象，没有磁性、大切向速度或快速自转的证据。因此，它很可能是通过单颗星星演化形成的，并且很可能有一个ONe核心。演化模型表明，它的内部有99%是结晶的。天文地震学为探测其内部结构提供了前所未有的机会。然而，相对较少的脉动模式检测限制了我们的能力，以获得强大的地震解决方案。相反，我们提供了几个代表性的解决方案，可以解释观察到的这颗星星的属性。广泛的后续时间序列测光的这个独特的目标有可能发现一个显着的额外的脉动模式，这将有助于克服退化的asteroseismic适合，使我们能够探测内部的一个1.3 M的结晶白色矮星。
We present Apache Point Observatory (APO) and Gemini time-series photometry of WD J004917.14−252556.81, an ultramassive DA white dwarf withK and logg= 9.34. We detect variability at two significant frequencies, making J0049−2525 the most massive pulsating white dwarf currently known withM⋆= 1.31 M⊙(for a CO core) or 1.26 M⊙(for an ONe core). J0049−2525 does not display any of the signatures of binary mergers, there is no evidence of magnetism, large tangential velocity, or rapid rotation. Hence, it likely formed through single star evolution and is likely to have an ONe core. Evolutionary models indicate that its interior is ≳99 per cent crystallized. Asteroseismology offers an unprecedented opportunity to probe its interior structure. However, the relatively few pulsation modes detected limit our ability to obtain robust seismic solutions. Instead, we provide several representative solutions that could explain the observed properties of this star. Extensive follow-up time-series photometry of this unique target has the potential to discover a significant number of additional pulsation modes that would help overcome the degeneracies in the asteroseismic fits, and enable us to probe the interior of an ≈1.3 M⊙crystallized white dwarf.