Cool Earths: Discovering Exoplanets beyond the Snow-line with Gravitational Microlensing

该提案提出了一个为期3年的引力微透镜项目，旨在发现行星系统寒冷外部区域的新系外行星，包括自由浮动的行星，以及可能围绕恒星残骸的行星。为了提高对较小质量（小于或等于10个地球质量）行星的灵敏度，我们提出了一种综合方法，将测量和同质机器人望远镜网络上的高节奏后续观测结合起来。尽管行星形成理论预测半长轴为几个或多个Au的行星应该很丰富，但它们超出了大多数行星发现技术的检测极限。直到今天，行星参数空间的这一重要区域仍在很大程度上未被探索。发现它们（或者可能发现那里的数量比预期的少）对于我们理解驱动行星形成的物理过程至关重要。结合微透镜技术的优势-即其对这类行星的独特敏感性-与拉斯坎布雷斯天文台（LCO）全球机器人望远镜网络的惊人能力，我们建议不仅要从地面观测中探测到雪线以外的小到地球质量的行星，而且还要描述它们的特征。

This proposal presents a 3-year gravitational microlensing project to discover new exoplanets in the cold outer regions of planetary systems, including free-floating planets and, potentially, planets around stellar remnants. For enhanced sensitivity to planets of smaller masses (small than or equal to 10 Earth masses), we propose an integrated approach that combines survey and high-cadence follow-up observations on a homogeneous network of robotic telescopes.Even though planet formation theories predict that planets with semi-major axes of a few or many AU should be abundant, they lie beyond the detection limits of most planet finding techniques. To this day, this important region of planetary parameter space remains largely unexplored. Discovering them (or possibly finding that there are few there than expected) is critical for our understanding of the physical processes that drive planet formation.Combining the strengths of the microlensing technique - namely its unique sensitivity to this type of planet - with the amazing capabilities of the Las Cumbres Observatory (LCO) global network of robotic telescopes, we propose to not only detect planets down to Earth-masses beyond the snow-line from ground-based observations, but also to characterize them.