RAPID: Multiwavelength Imaging and Spectroscopy of the Corona During the 2023 April 20 Total Solar Eclipse

日食提供了一个难得的机会来了解日冕。太阳的外层是一个谜--它有数百万度，比它下面的光球层热得多。这个快速反应研究(RAPID)项目将观测2023年4月20日在西澳大利亚埃克斯茅斯上空的日全食。这些观测将观察日冕结构，并将与高海拔天文台升级后的日冕多通道偏振仪数据以及美国宇航局帕克太阳探测器和太阳轨道器的现场测量结果进行比较。团队成员将积极参与这一研究领域的推广工作，研究生将接受这方面的培训。日全食使日冕结构从太阳表面到几个太阳半径的空间不间断覆盖，日冕发射在近紫外线、可见光和近红外，由辐射激发的发射线组成，以及电子和尘埃的连续散射。谱线和连续发射可以产生不同日冕等离子体成分的电子和离子温度、密度、离子丰度、非热运动和流出，从而对日冕加热过程的不同表现的动力学和热力学有价值的见解。在跨越三个太阳周期的观测中，发现在整个日冕中普遍存在的∼为1.2MK的Fe10+发射源与300~700 km/S的就地太阳风流有关。这些多波长观测还揭示了日冕动力学在驱动等离子体不稳定和日冕物质抛射中所起的作用，以及在日冕物质抛射锋面同时扩展到行星际空间时释放嵌入其中的冷物质。拟议的2023年4月20日日全食成像和光谱仪器将能够描述太阳周期25周上升活动期不同离子和中性物种的热力学性质。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。

Solar eclipses provide a rare opportunity to learn about the solar corona. This outer layer of the Sun is a mystery – it is millions of degrees and much hotter than the photosphere below it. This Rapid Response Research (RAPID) project will observe the 2023 April 20 total solar eclipse over Exmouth in Western Australia. The observations will observe coronal structures and will be compared with the High Altitude Observatory’s Upgraded Coronal Multi-Channel Polarimeter data and to in situ measurements from NASA’s Parker Solar Probe and Solar Orbiter. Team members will be actively engaged in outreach and graduate students will be trained in this research area.Total solar eclipses enable an uninterrupted spatial coverage of coronal structures from the solar surface out to several solar radii with coronal emission in the near ultraviolet, visible and near infrared, composed of radiatively excited emission lines, as well as continuum scattering by electrons and dust. Spectral line and continuum emission can yield the electron and ion temperature, density, ionic abundance, non-thermal motions and outflows of different coronal plasma constituents, hence valuable insights into the dynamics and thermodynamics of different manifestations of coronal heating processes. Ubiquitous sources of Fe 10+ emission at ∼ 1.2 MK throughout the corona are found to be invariably linked to 300 to 700 km/s in situ solar wind streams in observations spanning three solar cycles. These multiwavelength observations also unveil the role of prominence dynamics in driving plasma instabilities and CMEs, as well as releasing cool material embedded within CME fronts as they expand, in tandem, into interplanetary space. The proposed imaging and spectroscopic instrumentation for the 2023 April 20 total solar eclipse will enable the characterization of the thermodynamic properties of different ionic and neutral species during the rising activity phase of solar cycle 25.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.