Empirical Relations for the Sensitivities of Solar-like Oscillations to Magnetic Perturbations

Oscillation mode frequencies of stars are typically treated as static for a given stellar model. However, in reality they can be perturbed by time-varying sources such as magnetic fields and flows. We calculate the sensitivities of radial p-mode oscillations of a set of models for masses between 0.7 and 3.0 M-circle dot from the main sequence to the early asymptotic giant branch. We fit these mode sensitivities with polynomials in fundamental stellar parameters for six stages of stellar evolution. We find that the best-fitting relations differ from those proposed in the literature and change between stages of stellar evolution. Together with a measure of the strength of the perturbation, e.g. of the level of magnetic activity, the presented relations can be used for assessing whether a star's observed oscillation frequencies are likely to be close to the unperturbed ground state or whether they should be adjusted.