A Measurement of the Rotational Frequency Splitting of the Solar Five-Minute Oscillations.
Abstract
Observations of the solar five-minute acoustic oscillations were employed to probe the sub-surface rotation rate of the sun. The oscillations were observed in the solar photospheric velocity field. Full disk velocity images were obtained with a magneto-optical filter which employs magneto-optical effects in an atomic vapor of sodium to isolate alternate wings of a spectral line. The observations were obtained at the 60-foot Solar Tower of the Mt. Wilson Observatory during the summer of 1984. The time series of velocity images were analyzed to yield the rotational frequency splitting of oscillation modes with spherical harmonic degrees ranging from 5 to 120. These results show the solar rotation rate to decrease with depth inside the sun over the depth range studied. Also, the rate of differential rotation is observed to decrease with depth inside the sun.
- Publication:
-
Ph.D. Thesis
- Pub Date:
- 1988
- Bibcode:
- 1988PhDT.........1T
- Keywords:
-
- Physics: Astronomy and Astrophysics;
- Acoustic Frequencies;
- Solar Oscillations;
- Stellar Rotation;
- Velocity Distribution;
- Magneto-Optics;
- Photosphere;
- Time Series Analysis;
- Solar Physics