Connecting Eruptive Transients and Their Supernovae

研究人员将研究一类重要的大质量恒星，它们的表面有明亮的物质喷发。这些恒星处于恒星生命周期的最后阶段，有时就在作为超新星(SNE)的恒星爆炸之前。研究人员将使用亚利桑那大学的望远镜来研究发光蓝变星(LBV)。他们将研究近地天体周围喷出的物质，以及近地天体亮度之间的联系。来自LBV的物质看起来就像环绕恒星的明亮的气环。在用光学望远镜和灵敏相机进行观察时，这种材料是可见的。这些观测提供了测量喷发质量和速度的唯一方法，以及大喷发之间的典型时间段。研究人员将研究银河系及附近星系中LBV的环境。这位研究人员将在CAMPARE项目中担任导师，该项目通过招募少数族裔和在统计学上代表不足的群体来参加斯图尔德天文台的夏季本科生研究体验，以促进科学的多样性。这位调查员将继续担任天空大使，与图森市的小学和高中科学教师合作。作为该计划的一部分，他们将开发有关太阳和恒星、超新星以及元素起源的教学材料。这些研究项目还将资助一篇博士论文和几名本科生研究人员，为他们提供复杂的多波长观测数据和时变现象的经验。研究人员专注于观测，以了解恒星的生命周期和大质量恒星的爆炸性死亡，因为近地天体在星系中的反馈占主导地位。SNE丰富了星际介质中的元素，可以用于遥远宇宙的探测条件。使用SNE来估计到星系的距离取决于对大质量恒星及其产生的各种类型SNE之间的联系的理解。喷发质量损失对恒星演化有影响，而在核心坍塌之前的猛烈喷发可能会导致一些已知的最明亮的SNE。这种LBV/SNE的联系最初是有争议的，因为恒星模型将大质量的LBV放在了早期阶段，但最近观察到了LBV恒星和SNE之间的联系的戏剧性证实。2009年，一颗LBV恒星在一次大质量恒星调查中被发现，然后在2012年，这颗恒星成为了一颗核心崩塌的近地天体。类似LBV的喷发可能掌握着关于核燃烧最后阶段恒星不稳定性的关键线索，这对于理解核心塌陷至关重要。在这些研究中，研究人员将探测到大量的河外瞬变，并限制喷发的光度、质量损失率、持续时间和喷发速度。其中一些喷发的瞬变将很快爆发为SNE，因此这些观测对于理解大质量恒星核心塌缩的前奏将具有巨大的价值。

The investigators will study an important class of massive stars, which have bright eruptions of material from their surface. These stars are in the last stages of their stellar life cycle, sometimes just before stellar explosions as supernovae (SNe). The investigators will use telescopes of the University of Arizona to study Luminous Blue Variable (LBV) stars. They will study the material ejected around nearby LBVs and the connection between SNe brightnesses. The material from the LBVs appears as bright rings of gas surrounding the stars. The material is visible in observations with optical telescopes and sensitive cameras. These observations provide the only way to measure the ejected mass and speed, as well as the typical time period between large eruptions. The investigators will study the environments of LBVs in the Milky Way and nearby galaxies. The investigator will mentor in CAMPARE, a program that fosters diversity in science by recruiting minorities and statistically underrepresented groups for a summer undergraduate research experience at Steward Observatory. The investigator will continue as a Sky Ambassador, working with Tucson elementary and high-school science teachers. As part of this program, they will develop instructional materials concerning the Sun and stars, supernovae, and the origin of the elements. There research program will also fund one Ph.D. thesis and several undergraduate researchers, providing them with experience with complex multi-wavelength observational data and time-variable phenomena. The investigators focus on observations to understand the stellar life cycle and explosive deaths of massive stars, since SNe dominate feedback in galaxies. SNe enrich the interstellar medium with elements, and they can be used probe conditions in the distant universe. The use of SNe to estimate of distances to galaxies hinges upon understanding the connection between massive stars and the various types of SNe they produce. Eruptive mass loss is influential in stellar evolution, and violent eruptions preceding core collapse can lead to some of the most luminous SNe known. This LBV/SNe connection was initially controversial because stellar models place massive LBVs in an earlier phase, but recently a dramatic confirmation of the connection between LBV stars and SNe was observed. In 2009 an LBV star was noted in a survey of massive stars, and then in 2012 this star became a core-collapse SNe. LBV-like eruptions may hold critical clues about stellar instability during the final phases of nuclear burning, vital to understanding core collapse. During these studies, the investigators will detect a large number of extragalactic transients, and constrain the luminosity, mass-loss rates, duration, and outflow speed of the eruptions. Some of these eruptive transients will soon explode as SNe, so the observations will have tremendous value for understanding the prelude to core collapse of massive stars.