The term “ultraviolet (UV) burst” is introduced to describe small, intense, transient brightenings in ultraviolet images of solar active regions. We inventorize their properties and provide a definition based on image sequences in transition-region lines. Coronal signatures are rare, and most bursts are associated with small-scale, canceling opposite-polarity fields in the photosphere that occur in emerging flux regions, moving magnetic features in sunspot moats, and sunspot light bridges. We also compare UV bursts with similar transition-region phenomena found previously in solar ultraviolet spectrometry and with similar phenomena at optical wavelengths, in particular Ellerman bombs. Akin to the latter, UV bursts are probably small-scale magnetic reconnection events occurring in the low atmosphere, at photospheric and/or chromospheric heights. Their intense emission in lines with optically thin formation gives unique diagnostic opportunities for studying the physics of magnetic reconnection in the low solar atmosphere. This paper is a review report from an International Space Science Institute team that met in 2016–2017.

中文翻译：

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太阳紫外线爆发

引入术语“紫外线 (UV) 爆发”是为了描述太阳活动区域的紫外线图像中的小而强烈的瞬态增亮。我们盘点它们的属性并提供基于过渡区域线中的图像序列的定义。日冕特征是罕见的，大多数爆发都与小规模的、抵消了出现在新兴通量区域的光球层中的相反极性场、太阳黑子护城河中的移动磁特征和太阳黑子光桥有关。我们还将紫外线爆发与之前在太阳紫外光谱法中发现的类似过渡区现象以及光学波长下的类似现象（特别是艾勒曼炸弹）进行了比较。类似于后者，紫外线爆发可能是发生在低层大气、光球层和/或色球层高度的小规模磁重联事件。它们在光学薄层中的强烈发射为研究低太阳大气中磁重联的物理学提供了独特的诊断机会。本文是国际空间科学研究所团队于 2016-2017 年会面的综述报告。