A Study of Helical Oscillations in Sunspots
Abstract
On the basis of observations and published data of 17 sunspots helical oscillations of different type have been detected: close to harmonic, and increasing and decreasing with time (Figure 1a). The mean period of oscillations is T=7.1 ± 3.0 days, mean amplitude A=40+/- 23 degrees, mean rotation rate C=17+/- 15 degrees per day. The depth of the penetration of the sunspot under the photosphere has been evaluated as 7500 km and the mass of oscillating portion of sunspot as M=2 x 1023 g using a simple mathematics model. The kinetic energy of rotation of sunspot is 1x1031 erg.
- Publication:
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Byulletin Solnechnye Dannye Akademie Nauk SSSR
- Pub Date:
- March 1985
- Bibcode:
- 1985BSolD...3...65P