Architectures and Weather of Exoplanetary Systems

第一张围绕其他恒星的行星的直接图像，给系外行星科学带来了重大的新推动力。它们不仅为了解其他行星系统的结构提供了前所未有的视角，而且还为直接表征系外行星大气奠定了基础。随着2014年大型地面望远镜上的极端对比度成像技术的出现，以及2018年詹姆斯·韦伯太空望远镜的发射，系外行星的研究正在进入一个新的阶段。我的研究处于有利地位，可以利用这些科学发展。长期以来，我一直在研究系外行星系统和褐矮星的特征：褐矮星是质量更大的巨行星。我目前的工作目标是最近的系统，已知的星周碎片盘：类似于太阳系中小行星和彗星碎片产生的岩石和冰物质带。我还在进行规模最大、灵敏度最高的棕矮星云和风暴研究，以研究太阳系外世界的天气现象。这些都是nasa资助的研究项目，由我在石溪大学（Stony Brook University）的团队的不同成员进行，石溪大学是我以前的学术机构。我最近在西安大略大学担任加拿大系外行星研究主席，这为我在更广泛的目标下扩展和统一这些项目提供了机会。我研究的首要目标是为我们太阳系的建筑和进化创造一个全面的背景，并以此来解决它在居住方面有多独特的问题。我打算追求的具体主题建立在我目前的项目之上。我计划：(1)直接对围绕附近恒星运行的系外行星进行成像，并在与多普勒和凌日行星巡天探测的轨道重叠的大范围轨道间隔上确定它们的频率；(2)对星周碎片盘的尘冰形态进行空间解析，揭示碎片盘与嵌入行星之间的动力学相互作用；(3)研究褐矮星和系外行星大气中的云量和天气现象，以了解其大气动力学，并最终确定潜在宜居环境中大气现象的多样性。这项研究充分利用了地面望远镜上新的极端对比度成像能力：8米双子座南望远镜上的双子座行星成像仪和5米帕洛玛黑尔望远镜上的PALM-3000自适应光学系统。这些将允许太阳系外行星的常规成像，恒星周围环境的分辨率映射，以及对直接成像的行星的精确监测，以辨别大气风暴引起的微小通量变化。我的团队拥有罕见的优势，可以同时使用这两个设施，确保我们的研究项目取得更快的进展，覆盖更广泛的范围——包括北半球和南半球。加上我正在寻求的安大略省早期研究人员奖的支持，在未来的五年里，我将培养两名博士后，三名博士生，三名硕士研究生和十名本科生。在该计划的过程中，这些学员将获得先进的技术、计算和分析技能，这些技能对系外行星天文学的研究至关重要，但也为天文学或学术界以外的领域的专业实现打开了大门。

The first direct images of planets around other stars have imparted a major new thrust to exoplanetary science. Not only have they offered unprecedented views into the structure of other planetary systems, but they have set the stage for the direct characterization of exoplanetary atmospheres. With extreme-contrast imaging technology arriving on large ground-based telescopes in 2014, and with the James Webb Space Telescope launching in 2018, the study of exoplanets is entering a new phase. My research is well-positioned to take advantage of these science-enabling developments. I have had a long-standing involvement in the study of exoplanetary systems and the characterization of brown dwarfs: giant planets' more massive kin. My current work targets the nearest systems with known circumstellar debris disks: belts of rocky and icy material analogous to that produced by asteroid and comet debris in the Solar System. I am also conducting the largest and most sensitive study of clouds and storms in brown dwarfs to study weather phenomena on extrasolar worlds. These are NASA-funded research projects that are being carried out by various members of my team at Stony Brook University: my former academic institution. My recent move into the position of Canada Research Chair in Extrasolar Planets at the University of Western Ontario has opened an opportunity to expand and unify these projects under a broader aim. The overarching goal of my research is to create a comprehensive context for the architecture and evolution of our Solar System, and to so address the question of how unique it is in being inhabited. The concrete themes that I propose to pursue build on my current projects. I plan: (1) to directly image extrasolar planets around nearby stars and to establish their frequency over a wide range of orbital separations that overlaps with the orbits probed by Doppler and transit-planet surveys; (2) to spatially resolve the dust-and-ice morphology of circumstellar debris disks in order to reveal the dynamical interactions of the disks with embedded planets; and (3) to study the cloud cover and weather phenomena in brown dwarf and exoplanetary atmospheres in a drive to understand their atmospheric dynamics and to ultimately establish the diversity of atmospheric phenomena in potentially habitable environments. The research takes full advantage of new extreme-contrast imaging capabilities being commissioned on ground-based telescopes: the Gemini Planet Imager on the 8 m Gemini South telescope and the PALM-3000 adaptive optics system on the 5 m Palomar Hale telescope. These will allow the routine imaging of extrasolar planets, the resolved mapping of circumstellar environments, and the precise monitoring of directly imaged planets to discern the minute flux variations cased by atmospheric storms. My team has the rare advantage of access to both of these facilities, ensuring faster progress and a broader scope—covering both the northern and the southern hemispheres—for our research program. Together with support that I am seeking through an Ontario Early Researcher Award, over the coming five years I will train two postdoctoral fellows, three PhD students, three MSc students, and ten undergraduates. In the course of the program these trainees will acquire advanced technical, computational, and analytical skills that are essential for research in exoplanetary astronomy, but that also open doors for professional realization in fields well outside of astronomy or academia.