Doppler oscillations in solar prominences simultaneously observed with two telescopes. Discovery of a 30 S oscillation
Time series of Doppler shifts are observed simultaneously with two telescopes in order to separate actual solar velocities from influences of image motion or unperfect guiding. Several maxima of the power contours occur only in the data set from one of the two telescopes and may thus originate from non-solar sources. Considering only those power maxima which are observed with both telescopes we establish the solar origin of periods near 20 and 12 min, which may be identified with `hybrid fast modes' from model calculations. For one prominence a significant period of 30 5 is detected which theory predicts as a wave guided by the prominence fine-structures. Our prominence oscillations are restricted to spatially small areas of a few arc see diameter.
Astronomy and Astrophysics
- Pub Date:
- October 1993
- sun: prominences - sun: oscillations