Formation of terrestrial planets in close binary systems: The case of alpha Centauri A
Formation of terrestrial planets in close binary systems: The case of alpha Centauri A
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DOI：
10.1051/0004-6361:20021357
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发表时间：
2002-09
影响因子：
6.5
通讯作者：
M. Barbieri;F. Marzari;H. Scholl
中科院分区：
文献类型：
--
作者：
M. Barbieri;F. Marzari;H. Scholl
目前，在密近双星系统中是否存在行星仍然是一个有争议的问题。尽管有伴星星星的强大引力扰动，行星体还能形成吗？本文通过数值模拟研究了密近双星系统的原型α Cen系统中行星形成的最后阶段，即从胚胎到类地行星的过程。我们发现类地行星可以在5000万年的时间尺度上围绕α Cen A生长。在我们的一些数值模型中，行星直接在低偏心率轨道上的星星的可居住区中形成。在一个模拟中，最后两颗行星处于2：1的平均运动共振状态，然而，在2亿年后变得不稳定。在形成过程中，一些行星胚胎落入恒星，可能会改变它们的金属丰度。
At present the possible existence of planets around the stars of a close binary system is still matter of debate. Can planetary bodies form in spite of the strong gravitational perturbations of the companion star? We study in this paper via numerical simulation the last stage of planetary formation, from embryos to terrestrial planets in the α Cen system, the prototype of close binary systems. We find that Earth class planets can grow around α Cen A on a time-scale of 50 Myr. In some of our numerical models the planets form directly in the habitable zone of the star in low eccentric orbits. In one simulation two of the final planets are in a 2:1 mean motion resonance that, however, becomes unstable after 200 Myr. During the formation process some planetary embryos fall into the stars possibly altering their metallicity.