A Systematic Large-Scale Survey of the Overlooked Population of Small Objects Between the Orbits of the Outer Planets.

半人马座是居住在木星和海王星之间的不稳定轨道上的小天体。它们已经被分散到远离太阳的原始轨道之外，并提供了一个机会来了解与它们有关的更遥远物体的性质。了解这些天体将使天文学家有机会限制太阳系形成的模型。PI和她的团队将使用Pan-STARRS目录中的数据来寻找更多的小型半人马座，并使用大型望远镜来研究这些物体。他们将寻找这些半人马座显示出某种彗星般活动的迹象，并将使用数值模型来解释这种活动。PI将与行星科学研究所的专业教育工作人员合作，为亚利桑那州南部3-8年级的教师开发和提供为期3天的研讨会。该团队将利用来自一个单一的，具有良好特征的全天空调查Pan-STARRS 1的数据进行系统的半人马座人口研究，这将使他们能够通过计算他们的去偏尺寸频率分布（SFD）来阐明半人马座从散射盘到木星家族彗星的演变，并更好地了解半人马座动力学历史对其活动的影响。他们将：1）在Pan-STARRS 1探测目录中搜索新的半人马座以获得机会目标，并收集统计上足够的样本用于计算去偏的尺寸-频率分布; 2）用合成半人马座模型对Pan-STARRS 1调查偏差进行建模，并将所得的探测效率应用于真实的数据，以计算下至更大尺寸区域的去偏SFD; 3）对具有广泛近日点距离的半人马座进行深度成像观测，以使用光度分析和数值尘埃建模来搜索和描述其活动;和4）运行动力学积分并利用热模拟来研究半人马座活动与其轨道历史的相关性，该奖项反映了NSF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。

Centaurs are small bodies residing on unstable orbits between Jupiter and Neptune. They have been scattered out of their original orbits far from the Sun and offer an opportunity to learn about the nature of the more distant objects to which they are related. Understanding these objects will give astronomers an opportunity to constrain models of Solar System formation. The PI and her team will use data from the Pan-STARRS catalog to find more small Centaurs as well as using large telescopes to study these objects. They will look for signs that these Centaurs show some sort of comet-like activity, and they will use numerical models to explain this activity. The PI will work with professional education staff at the Planetary Science Institute to develop and deliver 3-day workshops to teachers of grades 3-8 in southern Arizona. The team will conduct a systematic Centaur population study utilizing data from a single, well-characterized all-sky survey, Pan-STARRS1, that will allow them to shed light on the evolution of Centaurs from the Scattered Disk to Jupiter Family Comets by calculating their debiased size-frequency distribution (SFD), and to better understand the effects of dynamical history of Centaurs on their activity. They will: 1) Search for new Centaurs in the Pan-STARRS1 detection catalog to obtain targets of opportunity, and to collect a statistically adequate sample for calculating a debiased size-frequency distribution; 2) model the Pan-STARRS1 survey biases with a synthetic Centaur model and apply the resulting detection efficiency to the real data in order to calculate a debiased SFD down to kilometer-size regime; 3) make deep-imaging observations of Centaurs with a wide range of perihelion distances to search for and to characterize their activity using photometric analysis and numerical dust modeling; and 4) run dynamical integrations and utilize thermal modeling to investigate correlations of Centaur activity with their orbital history, with implications for the activity triggers and composition.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.