Detection of Extrasolar Planets by Gravitational Microlensing
Detection of Extrasolar Planets by Gravitational Microlensing
复制标题
利用引力微透镜探测太阳系外行星
DOI：
10.1007/978-3-540-74008-7_3
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发表时间：
2009
期刊：
影响因子：
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通讯作者：
D. Bennett
中科院分区：
文献类型：
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作者：
D. Bennett
引力微透镜提供了一个独特的窗口的属性和流行的太阳系外行星系统，因为它能够找到低质量的行星在几个Au的分离。来自微透镜的早期证据表明，迄今为止发现的最常见的系外行星类型是所谓的超级地球行星，其质量为10个地球，与其宿主恒星的距离为几个Au。探测到两颗这样的行星表明，大约有三分之一的恒星有这样的行星在1.5-4 Au的距离范围内，这比这些距离的气体巨行星的普遍性大一个数量级。我们回顾了微透镜方法的基本物理学，并说明了为什么这种方法允许在2-3 Au的地面观测分离的地球质量的行星的检测。我们探索的条件，允许检测的行星宿主恒星，并允许测量行星轨道参数。最后，我们表明，一个低成本的，基于空间的微透镜调查可以提供一个全面的统计普查的太阳系外行星系统的灵敏度下降到0.1地球质量的分离范围从0.5 Au到无穷大。
Gravitational microlensing provides a unique window on the properties and prevalence of extrasolar planetary systems because of its ability to find low-mass planets at separations of a few AU. The early evidence from microlensing indicates that the most common types of exoplanet yet detected are the so-called super-Earth planets of 10 Earth-masses at a separation of a few AU from their host stars. The detection of two such planets indicates that roughly one third of stars have such planets in the separation range 1.5–4 AU, which is about an order of magnitude larger than the prevalence of gas-giant planets at these separations. We review the basic physics of the microlensing method, and show why this method allows the detection of Earth-mass planets at separations of 2–3 AU with ground-based observations. We explore the conditions that allow the detection of the planetary host stars and allow measurement of planetary orbital parameters. Finally, we show that a low-cost, space-based microlensing survey can provide a comprehensive statistical census of extrasolar planetary systems with sensitivity down to 0.1 Earth-masses at separations ranging from 0.5 AU to infinity.