Solar flares are sudden flashes of brightness on the Sun and are often associated with coronal mass ejections and solar energetic particles that have adverse effects on the near-Earth environment. By definition, flares are usually referred to as bright features resulting from excess emission. Using the newly commissioned 1.6?m New Solar Telescope at Big Bear Solar Observatory, we show a striking "negative" flare with a narrow but unambiguous "dark" moving front observed in He i 10830 ?, which is as narrow as 340 km and is associated with distinct spectral characteristics in Hα and Mg ii lines. Theoretically, such negative contrast in He i 10830 ? can be produced under special circumstances by nonthermal electron collisions or photoionization followed by recombination. Our discovery, made possible due to unprecedented spatial resolution, confirms the presence of the required plasma conditions and provides unique information in understanding the energy release and radiative transfer in astronomical objects.
展开▼
机译:太阳耀斑是太阳上突然的亮度闪烁,通常与日冕物质抛射和太阳高能粒子有关,会对近地环境产生不利影响。根据定义,耀斑通常被称为由于过度发射而产生的明亮特征。在大熊太阳能天文台使用新近调试的1.6?m新太阳望远镜,我们展示了一个引人注目的“负”耀斑,在He i 10830?中观察到了狭窄但清晰的“暗”移动锋,其狭窄至340 km,与Hα和Mg ii谱线的明显光谱特征有关。从理论上讲,He i 10830中的这种反差?可以在特殊情况下通过非热电子碰撞或光电离再复合而产生。我们的发现由于空前的空间分辨率而成为可能,它证实了所需的等离子体条件的存在,并为了解天文学物体的能量释放和辐射传递提供了独特的信息。
展开▼