Collaborative Research: Using Spectroscopy of Light Echoes to Observe the 19th Century Great Eruption of Eta Carinae

这个项目将对著名的大质量恒星船底座埃塔在19世纪的大喷发进行详细的光谱研究，目标是在爆发发生160年后发现的轻回波。船底座埃塔火山是一类非末梢喷发的原型，这种喷发主导着大质量恒星的质量损失，并与猛烈的前超新星抛射有关，这些超新星抛射产生了宇宙中最明亮的超新星。我们对其喷发的经验信息仅限于对其视觉亮度的历史描述，因为当喷发发生时，天文光谱仪还没有发明出来。然而，我们最近发现的来自船底座埃塔的光回声为我们提供了一个用现代仪器重新观察的独特机会，因为19世纪喷发的光从周围恒星形成区域附近的尘埃云中反弹，现在到达了我们这里。通过观察我们已经发现的多个光回波，我们将产生19世纪长达20年的船底座埃塔喷发的详细光谱时间序列，包括短暂的亮化事件，峰前和峰之间的平静时间，以及长时间的亮相。了解船底座埃塔的3D效果将有助于我们对缺乏空间分辨率的几何学信息的河外事件进行建模。我们将直接测试和完善喷发理论，包括非末端爆炸和高于爱丁顿极限的密集连续统驱动风。这项研究也是非常及时的：它将使人们对喷发瞬变源的兴趣迅速增长，目前的瞬变调查和对LSST的预测，它将为已知最明亮的超新星之前(在JWST努力探测它们的高红移时)来自超大质量恒星的喷发提供重要线索，它将为最近提出的一些关于船底座埃塔喷发本身的模型提供直接测试。该计划的广泛科学影响有几个方面。它将提供关于一颗著名的大质量恒星及其历史事件的独特和及时的信息，这是理解宇宙中的瞬变现象、与非末日瞬变事件相关的爆发和爆炸及其在恒星生死中所起作用的基准。在STSCI公共推广部门的帮助下，我们还将制作一系列YouTube视频，由团队成员向非专业观众解释项目的关键方面。对于传统上在天文学领域代表性不足的群体，我们将通过参加美国国家科学基金会资助的亚利桑那州和加州保利波莫纳大学之间的CAMPARE交流项目，招募少数族裔本科生直接从事这项研究，而亚利桑那州打算由这笔资金资助的研究生是女性。

This program will perform a detailed spectroscopic study of the 19th century Great Eruption of the famous eruptive massive star Eta Carinae, by targeting light echoes discovered 160 years after the outburst occurred. Eta Carinae is the prototype for a class of non-terminal eruptions that dominate mass loss in massive stars and have been linked to violent pre-supernova ejections that yield the most luminous supernovae in the universe. Our empirical information about its eruption has been limited to historical accounts of its visual brightness, since the astronomical spectrograph had not yet been invented when the eruption occurred. However, our recent discovery of light echoes from Eta Carinae provides a unique opportunity to get a second look with modern instruments, because light from the 19th century eruption bounced off nearby dust clouds in the surrounding star-forming region, reaching us now. By observing the multiple light echoes we have discovered, we will produce a detailed spectral time-sequence of the 20-yr long 19th century eruption of Eta Carinae, including brief brightening events, quiescent times before and between peaks, and long-duration bright phases. Understanding the 3D effects in Eta Carinae will help us model extragalactic events where we lack any spatially resolved information about geometry. We will directly test and refine theories for the eruption that involve non-terminal explosions and dense continuum-driven winds above the Eddington limit. This study is also quite timely: It will inform a rapidly-growing interest in eruptive transient sources fueled by current transient surveys and anticipation of LSST, it will provide important clues to the eruptions from very massive stars that precede the most luminous supernovae known (in advance of JWST's efforts to detect them at high redshift), and it will provide direct tests of some very recently proposed models for the eruption of Eta Carinae itself.There are several aspects to the broad scientific impact of this program. It will provide unique and timely information about a famous massive star and its historical event that is a benchmark for understanding transient phenomena in the universe, eruptions and explosions associated with non-terminal transient events, and their role in the lives and deaths of stars. Aided by professional graphics and animations generated with the help of the STScI public outreach department, we will also produce a series of YouTube videos of team members explaining key aspects of the project for a non-specialist audience. Concerning traditionally underrepresented groups in astronomy, through participation in the NSF-funded CAMPARE exchange program between Arizona and Cal-Poly Pomona, we will recruit minority undergraduates to be directly engaged in the research, and the Arizona graduate student intended to be funded by this grant is female.