CAREER: Giant Planets in Dusty Disks

尘埃颗粒对生长中的行星及其宿主盘的影响远远超出了为行星内核提供种子材料的范围。颗粒决定了盘的垂直结构、盘的演化速率和主导行星的形成机制。PI和她的团队将把尘埃沉降和颗粒生长结合到一个随时间变化的原恒星盘模型中，并使用该模型来测试有关尘埃对行星形成影响的三个假设。首先，通过降低原恒星盘的尺度高度，颗粒的生长和沉降可能会限制由核心吸积形成的行星的质量低于木星。其次，颗粒的生长和沉降可能会引发先前稳定的圆盘的引力不稳定，因为它增加了圆盘对自身辐射的透明度。第三，在中红外区域，橄榄石颗粒不透明度随铁丰度增加而增加，随镁丰度降低。主要的行星形成机制可能取决于星盘物质的[Mg/Fe]比率。PI将通过启动新轨道计划，将她对行星形成的研究转化为对一年级大学生的教育充实，该计划每年由20名学生组成，他们将形成一个以行星科学为中心的学习社区。“新轨道”项目旨在帮助即将入学的学生对自己从事科学事业的能力充满信心。新轨道学院的学生将每周与PI一起参加一次研讨会，并在每学期一起上天文学和地质学课程，以在学习行星科学基础知识的同时完成他们的一般科学要求。新轨道计划的顶点将是每年到麦克唐纳天文台进行实地考察，以了解82英寸望远镜的历史和正在进行的行星研究。

The influence of dust grains on growing planets and their host disks extends far beyond providing seed material for planet cores. Grains determine the disk vertical structure, disk evolution rate, and dominant planet formation mechanism. The PI and her team will incorporate dust settling and grain growth into a time-evolving protostellar disk model and use the model to test three hypotheses relating to the influence of dust on planet formation. First, grain growth and settling, by lowering the scale height of the protostellar disk, may restrict planets forming by core accretion to sub-Jupiter masses. Second, grain growth and settling may trigger gravitational instability in a disk that was previously stable by increasing the disk's transparency to its own radiation. Third, olivine grain opacity increases with iron abundance and decreases with magnesium abundance in the mid-infrared, where the disk radiates heat generated by viscous turbulence. The dominant planet formation mechanism may depend on the [Mg/Fe] ratio of the star-disk material.The PI will translate her research on planet formation into educational enrichment for first-year college students by starting the New Orbits program, a cohort of 20 students each year who will form a learning community centered on planetary science. The New Orbits program is designed to help incoming students feel confident in their ability to pursue a career in science. New Orbits students will attend a weekly seminar with the PI and take astronomy and geology classes together each semester to fulfill their general science requirement while learning the basics of planetary science. The capstone of the New Orbits program will be a yearly field trip to McDonald Observatory to learn about historic and ongoing planetary research at the 82 inch telescope.