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查伦的半径和大气约束来自对恒星隐蔽的观测
A A S Gulbis1, J L Elliot, M J Person
1Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139-4307, USA. gulbis@mit.edu
Nature
|January 7, 2006
概括
新的观测显示,冥王星的卫星哈伦的半径为606公里,密度为1.72gcm. 这些发现提供了对外太阳系进化和查伦形成的见解.
科学领域:
- 行星科学 行星科学
- 太阳系外层的进化过程
- 冥王星-哈伦系统动力学 冥王星-哈伦系统动力学
背景情况:
- 冥王星和沙龙的物理特征对于理解外太阳系进化至关重要.
- 之前对查伦半径和密度的估计是不确定的,数据有限.
- 恒星遮蔽观测提供了一些限制,但需要改进.
研究的目的:
- 为了准确地确定查伦的半径和密度.
- 为了调查查伦上是否存在显著的大气层.
- 改进冥王星 - 哈伦星系形成和演变的模型.
主要方法:
- 查伦对一个恒星遮蔽的多站观测.
- 对隐蔽光曲线的分析,以得出几何和物理参数.
- 根据衍生参数计算散装密度和岩石质量分数.
主要成果:
- 查伦的平均半径确定为606 +/- 8公里.
- 哈伦的散装密度计算为1.72 +/- 0.15 g cm(-3).
- 岩石质量分数估计为0.63 +/- 0.05;没有发现显著的大气层.
结论:
- 结果支持冥王星-哈伦星系的碰撞形成模型.
- 系统中的前身对象可能经历了差异化.
- 大型太阳系外层天体保留大气的可能性仍然是开放的.
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