Direct detection and characterization of extrasolar planets

太阳系外行星的直接探测和表征

• 批准号: 402106-2011
• 负责人: Graham, James
• 金额: $ 5.73万
• 依托单位: University of Toronto
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=487940
• 关键词: Direct; detection; characterization; extrasolar; planets

We propose to study exoplanets and dusty debris disks around nearby stars using high angular resolution and high dynamic range imaging. We focus on the Gemini Planet Imager (GPI) instrument, which is an "extreme" adaptive optics coronagraph that will image self-luminous exoplanets orbiting stars in the solar neighborhood. The first stage of this task includes preparation for and execution of exoplanet surveys with GPI. Although the youngest stars (<100 Myr) are the best targets, GPI has good sensitivity to exoplanets with ages up to 2 Gyr. These "adolescent" host stars are more numerous than their youthful cousins and therefore they are important because they offer the statistical riches necessary to characterize planet populations. Although the majority of young stars within 100 pc have been located, a much smaller fraction of < 2 Gyr stars have been identified. We will pursue the identification of young stars and constrain their ages in a spectroscopic survey of about 1500 stars. We will measure Ca II H&K and Li I 6707 Å line strengths, as well as stellar v sin i and radial velocities. The second stage of this investigation involves actual observing with GPI to identify candidate exoplanets. We will conduct three core surveys that will: 1) establish the abundance of planetary systems; 2) test the core accretion model by conducting a census of regions where gas giants can only form via gravitational instability; 3) shed light on the origin of hot Jupiters by finding planets that migrated outwards; 4) show whether or not the architecture of our own planetary system is unique. The third stage involves confirmation and characterization of the candidates found using astrometry and spectroscopy. Once physical association has been confirmed the final phase involves measurement of atmospheric properties (effective temperature, gravity, and composition) and preliminary estimates of orbital elements. Each part of the proposed work is designed to attract the best students to pursue graduate research and engage them at the highest levels; it is planned that four PhD thesis will result from this program.

我们建议使用高角分辨率和高动态范围成像来研究系外行星和附近恒星周围的尘埃碎片盘。我们专注于双子座行星成像仪（GPI）仪器，这是一个“极端”的自适应光学日冕仪，将图像自发光的系外行星在太阳附近的恒星轨道。这项任务的第一阶段包括准备和执行与GPI的系外行星调查。虽然最年轻的恒星（<1亿年）是最好的目标，但GPI对年龄高达2 Gyr的系外行星具有良好的灵敏度。这些“青春期”的主星比它们年轻的兄弟星数量更多，因此它们很重要，因为它们提供了描述行星人口所需的统计财富。虽然大多数在100 pc以内的年轻恒星已经被定位，但只有一小部分< 2 Gyr的恒星被发现。我们将在大约1500颗恒星的光谱调查中识别年轻恒星并限制它们的年龄。我们将测量Ca II H&K和Li I 6707的X射线强度，以及恒星的v sin i和径向速度。这项调查的第二阶段涉及GPI的实际观测，以确定候选系外行星。我们将进行三次核心调查，将：1）建立行星系统的丰度; 2）通过对气体巨星只能通过引力不稳定性形成的区域进行普查来测试核心吸积模型; 3）通过寻找向外迁移的行星来阐明热彗星的起源; 4）显示我们自己的行星系统的结构是否独特。第三阶段涉及使用天体测量学和光谱学对发现的候选天体进行确认和表征。 一旦确认了物理关联，最后阶段将涉及测量大气特性（有效温度、重力和成分）和初步估计轨道要素。 拟议工作的每一部分都旨在吸引最优秀的学生从事研究生研究，并让他们参与最高水平的研究;计划将从该计划中产生四篇博士论文。