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| Paper: |
Running Penumbral Waves in Sunspots |
| Volume: |
184, Third Advances in Solar Physics Euroconference: Magnetic Fields and Oscillations |
| Page: |
103 |
| Authors: |
Christopoulou, E. B.; Georgakilas, A. A.; Koutchmy, Serge |
| Abstract: |
In order to study running penumbral waves, we analyzed high resolution sunspot observations obtained at the center and the wings of the Hα line. The sharp intensity gradient between the umbra and the penumbra has been removed by using an image processing technique. The processed images show the waves to start out from the umbral oscillating elements and to propagate outwards forming concentric circles around the elements. The propagation velocity is between 6 to 18 km s1; and the average period is about 190 sec. |
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