在热的海王星沙漠中留下的行星核心
David J Armstrong1,2, Théo A Lopez3, Vardan Adibekyan4
1Centre for Exoplanets and Habitability, University of Warwick, Coventry, UK. d.j.armstrong@warwick.ac.uk.
Nature
|July 3, 2020
概括
TOI-849b是一个比海王星小的密集系外行星, 它的低质量表明大气损失很大,
科学领域:
- 星球科学
- 外行星研究
- 天体物理学
背景情况:
- 巨大的行星内部和核心的了解很少,观测不确定性很大.
- 太阳系外行星经历了罕见的进化过程,
- 像HD149026b,LTT9779b和NGTS-4b这样的行星显示出大气损失和巨大的核心.
研究的目的:
- 研究外行星TOI-849b的性质,
- 通过内部结构模型确定TOI-849b的组成和进化历史.
- 了解巨大行星中可能发生的质量损失的机制.
主要方法:
- 对外行星TOI-849b的观测.
- 分析TOI-849b的质量,半径和密度.
- 应用内部结构模型来限制气体外质量.
主要成果:
- TOI-849b的半径小于海王星,但质量相当于地球的7.7倍,密度与地球相似.
- 内部结构模型表明和包裹不超过15%的行星总质量.
- 这颗行星的特征表明它曾经是一个气体巨星,
结论:
- TOI-849b可能是巨行星的剩余核心.
- 质量损失可能是通过热自我破坏,巨行星碰撞,或避免大量的气体积聚.
- 光蒸发可以在几十亿年内去除较小的/包裹,这意味着TOI-849b的剩余大气可能富含挥发性物质.
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