La Palma observations of umbral flashes
| Autor: | J.M. Krijger, P. Sütterlin, L. Rouppe van der Voort, Robert J. Rutten, P.J. Sloover |
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| Rok vydání: | 2003 |
| Předmět: |
Physics
Shock propagation Sunspot Astrophysics::High Energy Astrophysical Phenomena Astrophysics::Instrumentation and Methods for Astrophysics Dutch Open Telescope Astronomy Astronomy and Astrophysics Astrophysics Redshift Solar telescope Coherent wave Space and Planetary Science Observatory Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics |
| Zdroj: | Astronomy & Astrophysics. 403:277-285 |
| ISSN: | 1432-0746 0004-6361 |
| Popis: | We present high-quality Ca H & K data showing chromospheric flashes in sunspot umbrae collected with the Swedish Vacuum Solar Telescope, the Dutch Open Telescope, and the Swedish 1-m Solar Telescope at the Roque de los Muchachos Observatory on La Palma. Differential movies, time slices, spectrograms, and Fourier power maps demonstrate that umbral flashes and running penumbral waves are closely related oscillatory phenomena, combining upward shock propagation with coherent wave spreading over the entire spot. We attribute the flash brightening to large redshift by post-shock material higher up. We find no obvious relation between umbral dots and umbral flashes. |
| Databáze: | OpenAIRE |
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