How to interpret a sparse (i.e., incomplete) set of low-l p-mode frequencies?


Compare the observed oscillation spectrum to a vast and dense grid of stellar model oscillation spectra and pick out the closest match.



Guenther, D. B., 2004, “Quantitative Analysis of the Oscillation Spectrum of eta Boo,” ApJ, 612, 454

Guenther, D. B. and Brown, K. 2004, “Matching Stellar Models to Oscillation Data,” ApJ, 600, 419


Figure 1. Quicktime Movie shows schematically the code searching for matches between model frequencies and the MOST observed frequencies.

Figure 2. Chi-squared measure for the Sun (BiSON data (l = 0, 1, and 2)). A well-defined minimum exists, which coincides with known age of Sun. I.e., the age of the sun is determined solely from the p-mode frequencies.

Sun Chi squared verus age

Figure 3. Quicktime Movie showing chi-square results for alpha Cen (Bouchy & Carrier) ground based observations. Two distinct groups exist, one corresponding to models with convective cores and the other without.