Power Spectrum Analysis of Mount-Wilson Solar Diameter Measurements: Evidence for Solar Internal R-mode Oscillations

TL;DR

This study analyzes over 39,000 solar diameter measurements from Mount Wilson Observatory, revealing strong evidence of solar internal r-mode oscillations consistent with theoretical predictions.

Contribution

It provides the first power spectrum analysis linking observed solar diameter variations to specific r-mode oscillations in the Sun's interior.

Findings

Eight peaks match r-mode oscillation frequencies

Strong statistical significance with less than one in a million chance of random occurrence

Evidence supports the existence of internal solar oscillations

Abstract

This article presents a power-spectrum analysis of 39,024 measurements of the solar diameter made at the Mount Wilson Observatory from 1968.670 to 1997.965. This power spectrum contains a number of very strong peaks. We find that eight of these peaks agree closely with the frequencies of r-mode oscillations for a region of the Sun where the sidereal rotation frequency is 12.08 year$^{-1}$. We estimate that there is less than one chance in ten to the sixth power of finding this pattern by chance.