An Infrared Study of Comet Mineralogy and Temporal Activity

彗星矿物学和时间活动的红外研究

• 批准号: 0307466
• 负责人: Charles Woodward
• 金额: $ 27.67万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2007-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0307466&HistoricalAwards=false
• 关键词: Infrared; Study; Comet; Mineralogy; Temporal

AST 0307466WoodwardOne of the greatest challenges in modern astrophysics is to understand the conditions in protoplanetary disks during the epoch of planetesimal formation and the aggregation of planets. Comet nuclei are the frozen reservoirs of dust and ices from the early solar nebula. During a perihelion passage, solar irradiation enhances the production rate of volatile gases and creates a coma which enshrouds the nucleus. Entrained within the coma gases are dust grains lifted from the nucleus by the escaping gas. The dust grains may be released both from the nuclear surface and from deeper layers of the nucleus via jets. Surface dust grains may posses different properties from those particles dredged up from the interior of the comet due to the long term exposure of surface material to particle bombardment, irradiation, and to collisional evolution of the parent body. The primary research objective for this project lead by Dr. Charles Woodward, University of Minnesota, is to determine the grain properties of the early solar nebula by exploring the differences in grain properties between a) long period comets formed near Jupiter (and subsequently scattered into the Oort cloud by Jupiter), and b) short period comets formed at greater heliocentric distances (in the Kuiper Belt). In this project, appropriately bright comets will be observed at multiple epochs to ascertain whether the silicate mineralogy, relative mineral abundance, and particle size distribution of the ablated dust varies as a function of heliocentric distance. Special attention will be given to comets targeted for encounter with spacecraft. Comets selected for study include 2P/Encke, 9P/Tempel 1, 81P/Wild 2, as well as newly discovered comet C/2001 Q4 NEAT. The broad scientific objective is to advance the understanding of general comet properties and the evolution of small icy bodies in our solar system. Astronomy, in part because of its stunning imagery, provides a natural gateway for engagingthe public in scientific discussions and debates. Results of this cometary research program will be disseminated to the general public through a number of education and public outreach (EPO) activities. In addition, the research program creates an environment for student mentoring activities in experimental techniques and observational astrophysics. This participation often contributes to senior theses and helps to impart to aspiring astronomers (and/or students with scientific/technicalcareer objectives) observational and technical expertise, computer programming skills, andanalysis methodology. Ph.D. dissertations should result from data analysis and modeling activities associated with this program.***

在现代天体物理学中，最大的挑战之一是了解在小星子形成和行星聚集时期原行星盘的条件。彗核是来自早期太阳星云的尘埃和冰的冷冻储存库。在近日点通过时，太阳的辐射提高了挥发性气体的产生速度，并产生了一个昏迷，它将原子核包裹起来。在昏迷气体中夹带的是被逸出气体从彗核中带走的尘埃颗粒。尘埃颗粒可以通过喷流从核表面和核的更深层释放出来。由于表面物质长期暴露于粒子轰击、辐射和母体的碰撞演化，表面尘埃颗粒可能与从彗星内部挖出的颗粒具有不同的特性。这个项目的主要研究目标是由明尼苏达大学的Charles Woodward博士领导，通过探索a)在木星附近形成的长周期彗星（随后被木星分散到奥尔特云）和b)在更大的日心距离上形成的短周期彗星（在柯伊伯带）之间的颗粒特性的差异来确定早期太阳星云的颗粒特性。在这个项目中，将在多个时期观测适当亮度的彗星，以确定烧蚀尘埃的硅酸盐矿物学、相对矿物丰度和粒径分布是否随日心距离的变化而变化。将特别注意与航天器相遇的目标彗星。被选中研究的彗星包括2P/Encke、9P/Tempel 1、81P/Wild 2，以及新发现的彗星C/2001 Q4 NEAT。广泛的科学目标是促进对彗星的一般特性和我们太阳系中小冰体演化的理解。天文学，部分是因为其令人惊叹的图像，为公众参与科学讨论和辩论提供了一个天然的门户。该彗星研究项目的结果将通过一系列教育和公众宣传（EPO）活动向公众传播。此外，该研究项目为学生在实验技术和观测天体物理学方面的指导活动创造了一个环境。这种参与通常有助于撰写高级论文，并有助于向有抱负的天文学家（和/或有科学/技术职业目标的学生）传授观测和技术专长、计算机编程技能和分析方法。博士学位论文应与该计划相关的数据分析和建模活动有关