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Paper: |
Transition Region Oscillations in a Sunspot Region |
Volume: |
184, Third Advances in Solar Physics Euroconference: Magnetic Fields and Oscillations |
Page: |
146 |
Authors: |
Brynildsen, N.; Fredvik, T.; Kjeldseth-Moe, O.; Maltby, P. |
Abstract: |
Umbral oscillations in the sunspot transition region have been detected and described from SOHO observations, mainly taken with SUMER of NOAA 8156 on 18 February 1998 between 16:00 UT and 21:07 UT. SUMER recorded simultaneously in the transition regions lines O V λ629, N V λ1238 and N V λ1242, combined with long exposures for wavelength calibration. Transition region oscillations with periods close to 3 min were observed both in intensity and in line-of-sight velocity; the maximum intensity is nearly in phase with maximum velocity directed towards the observer. The wave characteristics appear to be compatible with the results of Gurman et al. (1982) from UVSP on SMM, who interpreted them as upward propagating acoustic waves. |
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