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，包括自由漂浮的行星，以及可能围绕恒星残骸的行星。为了提高对小质量行星（小于或等于10个地球质量）的灵敏度，我们提出了一种综合方法，将调查和高节奏的后续观测结合在一个均匀的机器人望远镜网络上。尽管行星形成理论预测，半长轴为几个或多个天文单位的行星应该是丰富的，但它们超出了大多数行星发现技术的探测范围。直到今天，这个重要的行星参数空间区域仍未被探索。发现它们（或者可能发现它们比预期的少）对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灵敏度，以及拉斯康布雷斯天文台（LCO）全球机器人望远镜网络的惊人能力，我们建议不仅可以从地面观测中探测到雪线以外的地球质量的行星，而且还可以对它们进行表征。

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.