一个靠近的巨行星逃脱了它的恒星的吞
Marc Hon1, Daniel Huber2,3, Nicholas Z Rui4
1Institute for Astronomy, University of Hawaii, Honolulu, HI, USA. mtyhon@hawaii.edu.
Nature
|June 28, 2023
概括
围绕类似太阳的恒星运行的行星可以在红巨星阶段生存. 发现一个围绕着燃烧的红色巨星运行的巨大行星, 挑战了关于行星在恒星进化过程中的生存的先前假设.
科学领域:
- 外行星科学
- 恒星进化
- 天文学
背景情况:
- 主序恒星膨胀成红色巨星, 通常会吞接近的行星.
- 在膨胀后的红色巨星周围没有短周期行星,这表明行星不会在这个阶段生存下来.
- 这种缺席被解释为反对围绕类似太阳的恒星生存的短周期行星的证据.
研究的目的:
- 为了研究核心燃烧红巨星周围行星的生存.
- 在恒星膨胀过程中被摧毁.
- 在恒星进化的先进阶段探索行星生存的替代方案.
主要方法:
- 发现和描述巨行星8小熊b.
- 分析行星的轨道距离 (0.5 AU) 与主星预测的红巨星半径 (0.7 AU).
- 评估轨道动力学和恒星进化模型以解释行星的生存.
主要成果:
- 发现一个巨大的行星,8小熊星b, 绕着一个核心燃烧的红色巨星运行.
- 这颗行星的近距离轨道 (0.5AU) 表明它应该在红巨星阶段被恒星吞没.
- 这颗行星几乎是圆形的轨道挑战了涉及遥远初始轨道的生存场景.
结论:
- 核心燃烧的红色巨星可以容纳近距离的行星,
- 8颗小熊座b的生存表明,可能发生了恒星的合并,改变了恒星的进化或创造了第二代行星.
- 这个系统提供了非正规的恒星进化在外行星系统的长期生存中发挥作用的证据.
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