Planets around White Dwarfs
Planets around White Dwarfs
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DOI：
10.1086/311546
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发表时间：
1998-07
期刊：
影响因子：
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通讯作者：
Jianke Li;L. Ferrario;D. Wickramasinghe
中科院分区：
文献类型：
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作者：
Jianke Li;L. Ferrario;D. Wickramasinghe
像我们这样的行星系统的命运，随着母星星膨胀通过红巨星阶段，成为一个白色矮星（WD），一直是一些讨论的话题。对于一个类地的内行星，即使外层发生严重的烧蚀，导电核心也可能保持完整。我们认为，行星的核心在轨道上围绕WD可能会揭示其存在，通过其与WD的磁层的相互作用。当行星穿过磁层时，将产生电流，这将加热WD磁极附近的大气。这种加热的结果可以在光学上被检测为Hα发射。欧姆耗散将导致行星轨道的缓慢衰减，这样的行星将在不到一个哈勃时间内与WD合并，除非初始轨道间隔大于10个太阳半径。我们认为WD GD 356这条奇特的发射线可能是这种并合过程中的一个系统。
The fate of a planetary system like our own, as the parent star expands through the red giant phase and becomes a white dwarf (WD), has been a topic of some discussion. For an Earth-like inner planet, the conducting core may remain intact, even though severe ablation occurs of the outer layers. We argue that a planetary core in orbit around a WD may reveal its presence through its interaction with the magnetosphere of the WD. As the planet moves through the magnetosphere, electrical currents will be generated, which will heat the atmosphere of the WD near its magnetic poles. The results of such a heating may be detected in the optical as Hα emission. Ohmic dissipation will result in the slow decay of the planetary orbit, and such a planet will merge with the WD in less than a Hubble time, unless the initial orbital separation is greater than about 10 solar radii. We propose that the peculiar emission-line WD GD 356 may be a system in the process of such a merger.