Eating Planets for Lunch and Dinner: Signatures of Planet Consumption by Evolving Stars
Eating Planets for Lunch and Dinner: Signatures of Planet Consumption by Evolving Stars
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DOI：
10.3847/1538-4357/ab5b00
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发表时间：
2019-09
期刊：
影响因子：
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通讯作者：
A. Stephan;S. Naoz;B. Gaudi;Jesus M. Salas
中科院分区：
文献类型：
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作者：
A. Stephan;S. Naoz;B. Gaudi;Jesus M. Salas
在恒星演化的所有阶段，都可以在恒星周围观察到系外行星，在许多情况下，它们的轨道配置最终会导致行星被其宿主恒星吞没或消耗，例如热彗星或超短周期行星。此外，像被污染的白色矮星这样的天体提供了强有力的证据，证明恒星消耗行星是一种常见的现象。这种消耗会导致恒星性质的一些重大变化，例如恒星自旋、光度、化学成分或质量损失过程的变化。在这里，我们探索这种广泛的各种影响的全面范围内的恒星和行星的质量和恒星演化的阶段，从红巨星的主要序列的白色矮星。我们确定，行星的消耗可以导致短暂的光度特征，持续数百年到数千年的顺序，并且消耗后的恒星自旋通常可以达到解体的速度。此外，恒星的质量损失可能是由这种自旋上升以及表面掠射相互作用引起的，导致形成不寻常的行星状星云形状或准直的恒星气体喷射。我们的研究结果突出了几个可观察到的恒星特征，通过这些特征可以推断出给定星星周围是否存在或以前是否存在行星。这将为未来的观测活动提供工具，以更好地限制系外行星的人口统计，以及行星的形成和演化历史。
Exoplanets have been observed around stars at all stages of stellar evolution, in many cases orbiting in configurations that will eventually lead to the planets being engulfed or consumed by their host stars, such as hot Jupiters or ultrashort period planets. Furthermore, objects such as polluted white dwarfs provide strong evidence that the consumption of planets by stars is a common phenomenon. This consumption causes several significant changes in the stellar properties, such as changes to the stellar spin, luminosity, chemical composition, or mass-loss processes. Here, we explore this wide variety of effects for a comprehensive range of stellar and planetary masses and stages of stellar evolution, from the main sequence over red giants to white dwarfs. We determine that planet consumption can cause transient luminosity features that last on the order of centuries to millennia, and that the post-consumption stellar spins can often reach breakup speeds. Furthermore, stellar mass loss can be caused by this spin-up, as well as through surface grazing interactions, leading to to the formation of unusual planetary nebula shapes or collimated stellar gas ejections. Our results highlight several observable stellar features by which the presence or previous existence of a planet around a given star can be deduced. This will provide future observational campaigns with the tools to better constrain exoplanet demographics, as well as planetary formation and evolution histories.