Solar flares are observed at all wavelengths from decameter radio waves to gamma-rays at 100 MeV. This review focuses on recent observations in EUV, soft and hard X-rays, white light, and radio waves. Space missions such as RHESSI, Yohkoh, TRACE, and SOHO have enlarged widely the observational base. They have revealed a number of surprises: Coronal sources appear before the hard X-ray emission in chromospheric footpoints, major flare acceleration sites appear to be independent of coronal mass ejections (CMEs), electrons, and ions may be accelerated at different sites, there are at least 3 different magnetic topologies, and basic characteristics vary from small to large flares. Recent progress also includes improved insights into the flare energy partition, on the location(s) of energy release, tests of energy release scenarios and particle acceleration. The interplay of observations with theory is important to deduce the geometry and to disentangle the various processes involved. There is increasing evidence supporting reconnection of magnetic field lines as the basic cause. While this process has become generally accepted as the trigger, it is still controversial how it converts a considerable fraction of the energy into non-thermal particles. Flare-like processes may be responsible for large-scale restructuring of the magnetic field in the corona as well as for its heating. Large flares influence interplanetary space and substantially affect the Earth's lower ionosphere. While flare scenarios have slowly converged over the past decades, every new observation still reveals major unexpected results, demonstrating that solar flares, after 150 years since their discovery, remain a complex problem of astrophysics including major unsolved questions. ELECTRONIC SUPPLEMENTARY MATERIAL Supplementary material is available for this article at 10.12942/lrsp-2008-1.

中文翻译：

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耀斑观察。

在从十米无线电波到100 MeV的伽马射线的所有波长下都可以观测到太阳耀斑。这篇综述着重于最近在EUV，软X射线和硬X射线，白光和无线电波中的观察。RHESSI，Yohkoh，TRACE和SOHO等太空任务已大大扩大了观测基础。他们揭示了许多惊喜：日冕源出现在发色层脚位的硬X射线之前，主要的耀斑加速位点似乎独立于日冕质量抛射（CME），电子和离子可能在不同的位点被加速，至少有3种不同的磁拓扑，基本特征从小火炬到大火炬都有所不同。最近的进展还包括对火炬能量分配，能量释放的位置，能量释放场景和粒子加速测试。观察值与理论的相互作用对于推断几何形状并弄清涉及的各个过程非常重要。越来越多的证据支持重新连接磁场线是根本原因。尽管该过程已被普遍认为是触发因素，但如何将相当一部分能量转换为非热粒子仍存在争议。类似耀斑的过程可能是电晕中磁场的大规模重组及其加热的原因。大耀斑会影响行星际空间，并会严重影响地球的下部电离层。在过去的几十年中，虽然耀斑的场景逐渐趋同，但每项新的观测结果仍然揭示出重大的意想不到的结果，表明太阳耀斑，自发现以来150年来，仍然是一个复杂的天体物理学问题，包括尚未解决的主要问题。电子补充材料本文的补充材料位于10.12942 / lrsp-2008-1。