Confirmation of the detection and classification of low-order, low-degree solar acoustic modes with the 1978 solar diameter observations

Abstract

The 1978 solar diameter observations of Caudell et al. (1980) have been examined for evidence of the low-order, low-degree acoustic modes found by Hill (1984) in the 1979 observations of Bos and Hill (1983). The 1978 power spectrum was tested for evidence of (1) a nonrandom distribution of peaks relative to the eigenfrequency spectrum found by Hill (1984), (2) spatial symmetry properties of the eigenfunctions for the modes classified by Hill (1984), and (3) a theta-dependence, specified by angular order m, of the amplitudes of oscillations for these same modes. The characterization of the symmetry properties of the eigenfunctions and the values of m were taken from the work of Hill (1984). The findings of these three tests confirm the detection of modes and their classifications as given by Hill (1984). These three tests are independent of each other and, when combined, furnish a confirmation of considerable statistical significance. In addition, these modes are found to be randomly excited; the average intrinsic line widths for the n = 1, l = 6, 8, 10, and 12 modes are > or =0.01 ..mu..Hz.