OBSERVATIONS OF INDIVIDUAL SOLAR EIGENMODES: THEIR PROPERTIES AND IMPLICATIONS.

Abstract

This work analyzes data taken in 1979 using a modification of the solar detector at SCLERA (Santa Catalina Laboratory for Experimental Relativity) designed to enhance spatial properties of the previously observed solar oscillations. Unlike previous solar observations taken at SCLERA, where the data consisted of single solar diameter measurements, the 1979 data consisted of six recorded limb profiles. This has important ramifications for the amount of signal present in the data which was generated by the terrestrial atmosphere, for the origin of the observed solar oscillations in fluctuations of the solar limb darkening function, and, most importantly, for the spatial symmetry properties of the observed solar eigenfunctions. The data consisted of 18 days of observations averaging ten hours per day and covering a total of 41 days. A linked Fourier transform of all 18 days was done for signal generated from each limb profile, and combinations of these six Fourier transforms made to increase sensitivity to symmetric or antisymmetric properties of the observed solar eigenmodes. The following results were found: 1. The observed oscillations are manifestations of fluctuations in the solar limb darkening function. 2. Terrestrial atmospheric contributions to the observed signal are negligible; thus, the sun constitutes the only possible source of the signal. 3. Given a resolution element of 1/(41 days) or 0.28 μHz, the solar oscillations observed represent individual solar eigenstates. 4. The spatial properties of the eigenstates are consistent with their interpretation in terms of spherical harmonics defined with respect to the observed solar rotational axis. 5. The eigenstates are temporally coherent for > 2 days and, in selected samples, for > 41 days. 6. The observed spacing of groups of eigenmodes is shown to be indicative of solar rotational effects; this spacing implies that the core of the sun is rotating approximately six times faster than the observed surface rotational velocity.