The Spin State of Comet 10P/Tempel 2

AST 0507601 MuellerBeatrice Mueller和Nalin Samarasinha博士将开展一个研究项目，结合他们在不同观测几何条件下获得的现有数据，确定观测良好的木星家族彗星10 P/Tempel 2的完整自旋状态。他们将证实（或反驳）穆勒和费林观测到的这颗彗星的周期变化。如果周期变化得到确认，他们将确定彗星10 P/坦普尔2是向上还是向下旋转。Mueller和Ferrin无法确定周期变化的意义。彗星应该旋转演化在理论上是没有争议的，但由于缺乏观测，模型没有受到限制。测量旋转周期的变化对于理解彗星的旋转状态和最终的自旋状态、彗星核的内部结构、它们的刚性以及机械能的阻尼效率的活动的影响具有深远的意义。彗核的内部结构与彗星的形成和演化有着密切的关系。 Mueller博士和Samarasinha博士的这项研究将为木星家族彗星的完整自旋状态添加到仅有几个自旋状态的小型现有数据库中。Mueller博士和Samarasinha博士还将使用数值光变曲线程序来研究彗星10 P/Tempel 2的周期变化是否不是由于旋转周期的实际变化，而是由于彗星处于稍微更高能量的非旋转状态。主轴自旋态大多数彗星被认为是在非主轴自旋状态，但这不是观察到的。这种差异有两个原因：（a）光变曲线观测不够准确，无法检测到轻微激发的自旋态和/或（B）阻尼时间和/或激发时间不正确。Drs Mueller和Samarasinha将指导一名本科生，该学生将在夏季完成与上述研究相关的重点项目，为学生提供本研究各个方面的经验。Mueller博士和Samarasinha博士将向行星数据系统的小天体节点提交彗星10 P/Tempel 2的图像和测光，该节点可以访问整个天文学界。他们的数据可以与早期和未来的数据相结合，这将增加他们的结果之外的科学回报。

AST 0507601MuellerDrs Beatrice Mueller and Nalin Samarasinha will pursue a research project to determine the complete spin state of the well observed Jupiter family comet 10P/Tempel 2 combining their existing data taken at different observing geometries. They will confirm (or refute) the period change of this comet observed by Mueller and Ferrin. If the period change is confirmed, they will determine if comet 10P/Tempel 2 is spinning up or down. Mueller and Ferrin were not able to determine the sense of the period change. That comets should evolve rotationally is in theory not disputed, but models are not constrained due to the lack of observations. The measuring of changes in rotational periods has profound implications for understanding the influence of activity on the rotational state and on the eventual spin states of comets, the interior structure of cometary nuclei, their rigidity, and the efficiency of damping of mechanical energy. The interior structure of cometary nuclei is ultimately related to the formation and evolution of comets. This research by Drs Mueller and Samarasinha will add a complete spin state for a Jupiter family comet to the small existing data base of only a few spin states.Drs Mueller and Samarasinha will also investigate using a numerical light curve program if the period change in comet 10P/Tempel 2 is not due to an actual change in rotational period but rather due to the comet being in a slightly more energetic non-principal axis spin state. Most comets are expected to be in a non-principal axis spin state but that is not what is observed. There are two reasons for this discrepancy: (a) light curve observations are not accurate enough to detect slightly excited spin states and/or (b) the damping times and/or excitation times are incorrect. Drs Mueller and Samarasinha will mentor an undergraduate student with a focused project related to the above research that can be completed during the summer providing the student with experience in every aspect of this research. Drs Mueller and Samarasinha will submit images and photometry of comet 10P/Tempel 2 to the Small Bodies Node of the Planetary Data System, which gives access to the entire astronomical community. Their data can be combined with earlier and future data which will increase the science return beyond their results.***