An Astronomical Time Machine: Light Echoes from Historic Supernovae

研究人员发现了一种研究超新星（SN）三维特性的方法，通过观察从尘埃细丝反弹后才到达地球的SN光。这些光的回声为天文学提供了一个独特的机会：直接观察同一天文事件的起因（爆炸）和结果（膨胀的残余）。由于光回波来自超新星周围的许多方向，因此可以构建该事件的3D模型。调查人员计划进行公众宣传讲座，为他们的研究提供视频总结，并为公众提供公民科学机会。光回波是一种新奇的现象，自然是对天文学历史、光传播时间、超新星爆炸物理学以及光谱学与历史亮度测量相比的优势的伟大介绍。他们正在开发供入门本科生使用的互动式学习材料。他们有一个令人兴奋的公民科学计划，使公众能够通过在他们的观察中识别新的光回声来学习科学过程。三维模型是有价值的，因为现代理论工作表明，不对称性可能是SN爆炸机制的关键因素。调查人员将扩大他们的计划，定期观察6个历史上的超新星事件。他们会和国家科学基金会一起观察吗？布兰科望远镜是一种大型望远镜，孔径为4米。3度的方形视野，加上20秒的DECam读数，这是搜索的理想望远镜。由于他们的目标通常比已经探测到的超新星更老，他们预计目标会稍微暗淡一些。它们一晚上会产生许多持续5分钟的图像。他们将使用经过机器学习编程的计算机来识别回声。他们将把他们的机器学习结果与公民科学对相同图像的分析进行比较。该奖项反映了美国国家科学基金会的法定使命，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。

The investigator has discovered a way to study the 3-dimensional (3D) properties of a Supernova (SN), by observing SN light that only now reaches Earth, after bouncing off dust filaments. These light echoes provide a unique opportunity in astronomy: direct observation of the cause (the explosion) as well as the effect (the expanded remnant) of the same astronomical event. Because the light echoes come from many directions around the supernovae, a 3D model of the event can be constructed.The investigators plan public outreach talks, video summaries of their research and citizen science opportunities for the public. The light echoes are novel events and are naturally great introductions to the history of astronomy, light travel time, SN explosion physics, and the advantage of spectroscopy compared to historical brightness measurements. They are developing interactive learning materials available for introductory undergraduates. They have an exciting Citizen Science plan, which enables the public to learn the scientific process by identifying new light echoes in their observations.The 3D model is valuable because modern theoretical work suggests that asymmetry may be a critical ingredient in the SN explosion mechanism. The investigators will expand their program to regularly observe 6 historical SN events. They will observe with the NSF?s Blanco telescope, a large telescope, with a 4-meter aperture size. The 3-degree square field of view, combined with the fast 20 second readout of DECam, this the ideal telescope for this search. Since their targets are generally older than already detected supernovae, they expect the targets to be slightly fainter. They will produce many 5 minute duration images a night. They will use computers programmed for machine learning to identify echoes. They will compare their machine learning results with Citizen Science analysis of the same images.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.