论文标题
白矮人的锂污染记录了一个阳性行星的积聚
Lithium pollution of a white dwarf records the accretion of an extrasolar planetesimal
论文作者
论文摘要
白矮人的潮汐破坏和随后对行星的积聚可以揭示超球星系统中岩石体的元素丰富性。这些丰度提供了有关系统形成的星云的组成的信息，类似于陨石丰度如何为我们对早期太阳系的理解提供理解。我们在白色矮人Gaia DR2的大气中报告了Li，Na，K和Ca的检测，我们将其归因于行星的积聚。使用模型大气，我们确定这些元素的丰度比，除了LI之外，它们与太阳系中的陨石值一致。我们将测得的LI丰度与旧恒星的测量和大爆炸核合成的期望进行了比较。
Tidal disruption and subsequent accretion of planetesimals by white dwarfs can reveal the elemental abundances of rocky bodies in exoplanetary systems. Those abundances provide information on the composition of the nebula from which the systems formed, analogous to how meteorite abundances inform our understanding of the early Solar System. We report the detection of Li, Na, K and Ca in the atmosphere of the white dwarf Gaia DR2 4353607450860305024, which we ascribe to accretion of a planetesimal. Using model atmospheres, we determine abundance ratios of these elements, and with the exception of Li, they are consistent with meteoritic values in the Solar System. We compare the measured Li abundance to measurements in old stars and to expectations from Big Bang nucleosynthesis.
