Oscillations and magnetic fields in the G8 star EK Eridani

Asteroseismology can provide information that is otherwise not easily accessible, like the stellar mass and the evolutionary stage. Strong magnetic fields are usually accompanied by rapid rotation, which makes asteroseismology difficult due to spectral line broadening. We have found what may turn out to be the Rosetta Stone of the stars: A slowly rotating solar-like star with a strong magnetic field. We have recently detected solar-like oscillations in this active sub-giant, but with amplitudes much lower than expected. We suggest that the large-scale magnetic field alters the pulsations, which become magneto-acoustic in nature. Here we present our results and discuss possible implications and how this may open up a new frontier in the studies of magnetic fields and stellar evolution.