SOLAR P-MODE FREQUENCIES AND THEIR DEPENDENCE ON SOLAR-ACTIVITY - RECENT RESULTS FROM THE BISON NETWORK

We present here high-accuracy determinations of the frequencies of low -l solar p-modes and their solar-cycle dependence. The data were obtai ned using the Birmingham network of solar spectrometers (BISON). The p recision of the measurements is discussed. Our previously published re sults of a significant frequency shift between solar minimum and solar maximum, apparently independent of l and similar to that found by oth er workers for intermediate-l modes, is confirmed and extended. This s uggests that at most only a small fraction of the variation is due to the solar core. Sets of frequencies at high and low solar activity, an d an average corrected for solar-activity effects, are presented. Ther e is now evidence that the solar-activity dependence of the frequencie s varies across the 5 minute spectrum.