The Birmingham Solar Oscillations Network (BiSON) provides high-quality high-cadence observations from as far back in time as 1978. Here we present the frequencies for the Sun-as-a-star global modes of oscillation.
2014 - Low-frequency, low-degree solar p-mode properties.
The solar low-degree low-frequency modes of oscillation are of particular interest as their frequencies can be measured with very high precision and hence provide good constraints on seismic models. Here we detect and characterize these valuable measures of the solar interior from a 22 yr Birmingham Solar Oscillations Network data set. We report mode frequencies, line widths, heights, amplitudes, and rotational splitting, all with robust uncertainties. The new values of frequency, rotational splitting, amplitude, and line width we provide will help place new constraints on hydrostatic and rotational structure, plus diagnostics of near-surface convection. Further to this, by assuming simple power laws, we extrapolate mode properties to lower frequencies. We demonstrate that the low-l low-frequency p modes have a low signal-to-noise ratio and that this cannot be overcome simply by continued observation. It will be necessary to observe the Sun in novel ways to ‘beat’ the intrinsic granulation noise.
2009 - Definitive Sun-as-a-star p-mode frequencies.
We present a list of ‘best possible estimates’ of low-degree p-mode frequencies from 8640 days of observations made by the Birmingham Solar-Oscillations Network (BiSON). This is the longest stretch of helioseismic data ever used for this purpose, giving exquisite precision in the estimated frequencies. Every effort has been made in the analysis to ensure that the frequency estimates are also accurate. In addition to presenting the raw best-fitting frequencies from our ‘peak-bagging’ analysis, we also provide tables of corrected frequencies pertinent to the quiet-Sun and an intermediate level of solar activity.
These are corrected frequencies pertinent to the quiet Sun.