Ichimoto K, Suematsu Y, Tsuneta S, Katsukawa Y, Shimizu T, Shine R A, Tarbell T D, Title A M, Lites B W, Kubo M, Nagata S
National Astronomical Observatory of Japan, 2-21-1, Osawa, Mitaka, Toyko 181-8588, Japan.
Science. 2007 Dec 7;318(5856):1597-9. doi: 10.1126/science.1146337.
The penumbra of a sunspot is composed of numerous thin, radially extended, bright and dark filaments carrying outward gas flows (the Evershed flow). Using high-resolution images obtained by the Solar Optical Telescope aboard the solar physics satellite Hinode, we discovered a number of penumbral bright filaments revealing twisting motions about their axes. These twisting motions are observed only in penumbrae located in the direction perpendicular to the symmetry line connecting the sunspot center and the solar disk center, and the direction of the twist (that is, lateral motions of intensity fluctuation across filaments) is always from limb side to disk-center side. Thus, the twisting feature is not an actual twist or turn of filaments but a manifestation of dynamics of penumbral filaments with three-dimensional radiative transfer effects.
太阳黑子的半影由众多纤细、呈放射状延伸的明暗细丝组成，这些细丝携带着向外的气流（埃弗谢德流）。利用太阳物理卫星“日出”号上搭载的太阳光学望远镜获取的高分辨率图像，我们发现了一些半影亮丝围绕其轴线做扭曲运动。这些扭曲运动仅在位于垂直于连接太阳黑子中心和太阳盘面中心的对称线方向的半影中被观测到，并且扭曲方向（即强度波动在细丝上的横向运动）总是从边缘侧向盘面中心侧。因此，这种扭曲特征并非细丝的实际扭转或转动，而是具有三维辐射转移效应的半影细丝动力学的一种表现。
