U.S.-China Cooperative Research (Astronomy): Joint Observa- tions of the Long-Term Evolution of Solar Magnetic Fields

美国加州理工学院Harold Zirin博士、Ken G. Libbrecht博士与北京天文台艾国祥、韩峰、刘建强教授关于“联合观测太阳磁场长期演变”的提案是由美国国家科学基金会和中国科学院联合主办的。在任何时候，太阳都被微弱的磁场覆盖着，这些磁场以一个30公里宽的元素网络的形式排列，被认为是由大规模的对流模式产生的。测量磁网寿命的尝试表明，这些元素的寿命约为50小时。当它们灭绝时，由什么来取代它们并不明显。不幸的是，每天短距离跑步的研究只提供了24小时中的10小时的良好数据，并且没有显示这些运动元素的来源。研究人员认为，解决这个问题的唯一办法是对这些磁场进行连续的观测。目前，只有大熊太阳天文台和怀柔太阳天文台的视频磁力计可以完成这项任务。该项目将利用两个站点的综合能力，覆盖每天24小时中的16小时，以跟踪油田的发展和运动。通过补充特拉维夫巡逻望远镜的数据，研究人员将能够跟踪几个24小时周期内小磁场的演变，并准确确定它们是如何演变的，从而对太阳日珥背后的磁性特征有了新的认识。

This proposal on "Joint Observations of the Long Term Evolution of Solar Magnetic Fields" between Dr. Harold Zirin and Dr. Ken G. Libbrecht of California Institute of Technology and Professors Ai Guoxiang, Han Feng, and Liu Jianqiang of the Beijing Astronomical Observatory, is jointly sponsored by NSF and by the Chinese Academy of Sciences. At all times the sun is covered with weak magnetic fields arranged in the form of a network of elements 30 km across, thought to be generated by a large scale convective pattern. Attempts to measure the lifetime of the magnetic network have indicated that the elements last about 50 hours. What replaces them when they die out is not obvious. Unfortunately, studies from short daily runs provide good data for only 10 out of 24 hours, and do not show what the source of these moving elements might be. The investigators believe the only solution for this problem is to obtain continuous observations of these magnetic fields. At present, only the videomagnetographs of the Big Bear Solar Observatory and the Huairou Solar Observatory can perform this task. The program will use the combined capability of the two sites to cover 16 of 24 hours per day to follow the development and motion of the fields. By supplementing this with data from a patrol telescope in Tel Aviv, the investigators shall be able to follow the evolution of the small magnetic fields for several 24 hour periods and determine exactly how they evolve, thus achieving a new understanding of the magnetic features which underlie solar prominences.