Every Datapoint Counts: Atmosphere-aided Flare Studies in the Rubin era

1859年，一场太阳风暴袭击了地球，扰乱了电报站，并在遥远的南方产生了可见的极光，一直到古巴。如果今天发生同样的风暴，将给世界电网和通信技术造成数万亿美元的损失。就在此之前，英国天文学家理查德·卡林顿观测到太阳表面突然变亮--这是第一次观测到太阳耀斑。像卡林顿观测到的这样的耀斑并不是太阳独有的，其他恒星也会出现，特别是那些比太阳更冷、质量更小的恒星。它们因能量、温度、持续时间和亮度的不同而不同。通过测量耀斑的特性，我们更接近于了解它们是如何工作的，以及它们如何影响行星维持生命的能力。特别是，测量耀斑的温度可以告诉我们它们对围绕其他恒星运行的行星大气的威胁程度。遗留的空间和时间调查(LSST)将在其10年的任务中观测到数百万次恒星耀斑。研究人员正在开发一种技术，利用地球大气来测量耀斑的颜色，从而测量温度。该项目还将资助林肯大学的一名学生对鲁宾数据进行“发声”。这种技术是通过声音来表示数据，以使盲人和视障人士(BVI)能够访问结果。即将到来的维拉·C·鲁宾天文台通过其遗留的空间和时间调查(LSST)提供了一个从天空中数百万颗恒星收集大型耀斑测量数据的机会。由于耀斑持续时间较短，调查节奏较慢，不太可能用一个以上的数据点探测到耀斑。该计划旨在开发一种方法来实现对恒星耀斑的LSST研究，重点是耀斑温度和温度演变，与耀斑的光度学形态相比，它们仍然缺乏约束。利用Rubin系统预期的精致图像质量和灵敏度，差分彩色折射可用于限制单历元探测的耀斑温度。将折射效应建模为大气柱密度、光度滤光片和耀斑温度的函数，在给定对LSST单次绝对天体测量精度的最低指定要求的情况下，在大气质量低至X=1.2的情况下，耀斑温度为10,000K或以上的单个g波段观测可以约束。在Rubin LSST为期10年的调查中，预计将在高于X=1.2的空气质量下收集近10万张g波段图像。该项目将开发一条管道来处理LSST数据并描述稀少观测到的耀斑温度的大样本，这将约束耀斑发射背后的物理过程的模型，以及耀斑参数(例如温度、持续时间、能量)和恒星参数(例如光谱类型、自转、磁场)之间的关系。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

In 1859, the Earth was struck by a solar storm that disrupted telegraph stations and created visible aurorae as far south as Cuba. If the same storm were to happen today, it would cause trillions of dollars in damage to the world’s power grids and communication technology. Just before the event, English astronomer Richard Carrington observed a sudden brightening of the Sun’s surface - the first observation of a solar flare. Flares such as the one Carrington observed are not unique to the Sun, but also occur on other stars, especially those cooler and less massive than the Sun. They vary across a range of energies, temperatures, durations, and brightness. By measuring the properties of flares, we come closer to understanding how they work and how they affect a planet’s ability to sustain life. In particular, measuring the temperature of flares can tell us the extent to which they threaten the atmospheres of planets orbiting other stars. The Legacy Survey of Space and Time (LSST) will observe millions of stellar flares over its 10-year mission. The investigators are developing a technique to use the Earth’s atmosphere to measure the color, and thus the temperature, of the flares. This project will also sponsor a student at Lincoln University to work on “sonification” of Rubin data. This technique is the representation of data through sound, to make the results accessible to Blind and Visually Impaired (BVI) persons. The upcoming Vera C. Rubin Observatory through its Legacy Survey of Space and Time (LSST) provides an opportunity to collect a large ensemble of flare measurements from millions of stars across the sky. Because of the short flare duration and the survey cadence, it is unlikely that flares will be detected with more than one data point. This program aims to develop a methodology to enable LSST studies of stellar flares, with a focus on flare temperature and temperature evolution, which remain poorly constrained compared to the photometric morphology of flares. Leveraging the exquisite image quality and sensitivity expected from the Rubin system, Differential Chromatic Refraction can be used to constrain flare temperature from a single-epoch detection. Modeling the refraction effect as a function of the atmospheric column density, photometric filter, and temperature of the flare, flare temperatures at or above 10,000K can be constrained by a single g-band observation at airmass as low as X=1.2, given the minimum specified requirement on single-visit absolute astrometric accuracy of LSST. Nearly 100,000 g-band images are expected to be collected at higher airmass than X=1.2 in the Rubin LSST 10-year survey. This project will develop a pipeline to process LSST data and characterize a large sample of sparsely observed flare temperatures, which will constrain models of the physical processes behind flare emission as well as the relationship between flare parameters (e.g. temperature, duration, energy) and stellar parameters (e.g. spectral type, rotation, magnetic field).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.