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arXiv 1111.2794astro-ph.EP
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近地双星和三星:自旋轨道性质的起源和演化

Near-Earth Binaries and Triples: Origin and Evolution of Spin-Orbital Properties

Julia Fang, Jean-Luc Margot

摘要:

在近地小行星群中,发现了具有相互轨道的双星和三星系统,这些轨道具有显著的偏心率和较大的半长轴。所有已知的具有偏心轨道的系统和所有广泛分离的主卫星对都具有快速旋转的卫星。在这里,我们研究的过程,可以阐明这些自旋轨道性质的起源。基于旋转裂变的双星形成模型可以在高偏心率和大范围分离的轨道上再现异步卫星,但与观测到的特性不匹配。我们探讨是否有任何进化机制可以链接的自旋和轨道参数预期裂变后的动力学今天观察到的。我们调查了四个过程:潮汐力矩,辐射扰动(BYORP),近距离行星相遇,和Kozai振荡。我们发现,裂变后的动力学和潮汐演化的组合可以解释几乎所有的自旋轨道性质的样本中的9个良好的特点近地双星和三重。其他机制可能起作用,但不需要解释观察到的数据。最后,我们描述了所观察到的自旋轨道状态,包括同步和圆形,异步和圆形,异步和偏心配置之间的演化途径。

英文摘要:

In the near-Earth asteroid population, binary and triple systems have been discovered with mutual orbits that have significant eccentricities as well as large semi-major axes. All known systems with eccentric orbits and all widely-separated primary-satellite pairs have rapidly rotating satellites. Here we study processes that can elucidate the origin of these spin-orbital properties. Binary formation models based on rotational fissioning can reproduce asynchronous satellites on orbits with high eccentricities and a wide range of separations, but do not match observed properties. We explore whether any evolutionary mechanisms can link the spin and orbital parameters expected from post-fission dynamics to those observed today. We investigate four processes: tidal torques, radiative perturbations (BYORP), close planetary encounters, and Kozai oscillations. We find that a combination of post-fission dynamics and tidal evolution can explain nearly all the spin-orbit properties in a sample of nine well-characterized near-Earth binaries and triples. The other mechanisms may act but are not required to explain the observed data. Lastly, we describe evolutionary pathways between observed spin-orbital states including synchronous and circular, asynchronous and circular, and asynchronous and eccentric configurations.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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