Origin and Evolution of the Polar Planets

人们已经发现许多围绕遥远恒星运行的行星，它们的轨道很奇怪，其特征是主恒星的旋转轴与行星的轨道之间存在巨大差异。由麻省理工学院领导的一个小组将探索这些行星的起源。这项工作将产生可通过詹姆斯·韦伯太空望远镜观测验证的预测。该团队将对波士顿大都会地区的当地高中和中学进行现场访问，重点关注最多样化和经济最落后的地区，使用便携式天文馆系统进行引人入胜的天文学演示，让学生无需前往专业天文馆或偏远地区即可体验黑暗天空的奇观。该教育项目将重点关注太阳系天体、附近恒星和行星。这些访问将拓宽学生对地球宇宙背景的看法，并激励学生在大学里学习STEM学科。极地行星中有相当一部分是温暖的海王星或超级海王星大小的行星，它们围绕着凉爽的恒星运行。这些极海王星有许多显著的特征：中等偏心和极轨道，位于所谓的热海王星沙漠内或附近，膨胀的大气层在许多情况下显示了质量损失的证据，以及在许多情况下存在外部大质量伴星的证据。该团队将对极地进行全面的理论分析，以充分了解其轨道和物理性质的起源。分析将跟踪行星的长期轨道演变，看看共振是否可以解释在最初的共振遭遇之后经过十亿年的演变后的今天的轨道特性。该小组将研究行星内部和大气对潮汐加热的反应，以解释目前的观测结果，并将轨道和内部模型结合在一起，得出极地海王星起源和长期演化的整体约束。这项工作将产生可通过大气观测验证的预测。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Many planets around distant stars have been found with strange orbits characterized by large differences between the axis of host star rotation and the orbit of the planet. A team led by the Massachusetts Institute of Technology will explore the origins of these planets. The work will yield predictions that are testable with observations by the James Webb Space Telescope. The team will undergo on-site visits to local high schools and middle schools in the Boston metropolitan area, with a focus on the most diverse and economically disadvantaged districts using a portable planetarium system to give engaging astronomy presentations that allow students to experience the wonders of a dark sky without having to travel to a professional planetarium or a remote location. The educational program will be focused on Solar System objects, nearby stars, and planets. The visits will broaden students’ perspectives about Earth’s cosmic context and inspire students to pursue STEM subjects in college.A sizable fraction of the polar planets are warm Neptune- or super-Neptune-sized planets orbiting cool stars. These polar Neptunes share a variety of distinguishing characteristics: moderately eccentric and polar orbits, locations in or near the so-called hot Neptune desert, puffy atmospheres that show evidence for mass loss in many cases, and evidence for exterior massive companion planets in many cases. The team will perform a comprehensive theoretical analysis of the polar to fully understand the origins of both their orbital and physical properties. Analysis will follow the long-term orbital evolution of planets to see whether resonance can explain present-day orbital properties after gigayears of evolution that follow an initial resonance encounter. The team will study the response of the planets’ interiors and atmospheres to tidal heating to explain present-day observations and will couple the orbital and interior models together to derive holistic constraints on the polar Neptunes’ origins and long-term evolution. The work will yield predictions that are testable with atmospheric observations.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.