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The properties of long-term sunspot oscillations.
- Source :
-
Astronomy Reports . May2014, Vol. 58 Issue 5, p328-334. 7p. - Publication Year :
- 2014
-
Abstract
- It is shown that neglecting the motion of sunspots in the plane of the sky in pixels of SOHO MDI magnetograms obtained for the vertical direction results in false periods of 700-1300 min in the long-term oscillations of the magnetic fields of sunspots observed near the central meridian (the Y artefact). The oscillation mode proposed by Efremov, Parfinenko, and Solov'ev in 2012 to be the lowest-frequency sunspot mode is an artefact. A proposed technique for monitoring this artefact using wavelet transforms can be used to study oscillation periods in the range 15 min < T < 500 min. The observational dependence of the oscillation frequency of the sunspot magnetic field on the field strength is constructed using observations of 45 sunspots. This dependence shows a multimode behavior that is consistent with earlier ground observations. One interpretation of this dependence based on the existence of four geometrical oscillation modes detected earlier is proposed. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 10637729
- Volume :
- 58
- Issue :
- 5
- Database :
- Academic Search Index
- Journal :
- Astronomy Reports
- Publication Type :
- Academic Journal
- Accession number :
- 95964499
- Full Text :
- https://doi.org/10.1134/S1063772914050047