Non-radial, non-adiabatic solar-like oscillations in RGB and HB stars

Poster (2012, July)

Corot and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. We compare the theoretical spectrum (amplitudes and life ... [more ▼]

Corot and Kepler observations of red giants reveal rich spectra of non-radial solar-like oscillations allowing to probe their internal structure. We compare the theoretical spectrum (amplitudes and life- times) of two red giants in the same region of the HR diagram but in different evolutionary phases. The lifetimes are obtained by computing theoretical non-adiabatic non-radial solar-like oscillations for mixed modes in the two models. Thanks to this, we have been able to compute the oscillation amplitudes through a stochastic excitation model. We present here our first results on the inertia, damping rates and amplitudes of the oscillations in the two stars and discuss the trapping, the visibilities and the am- plitudes of the different modes. The differences in the spectra of the two stars are also investigated. As already known, the period spacings in the two models are very different. Moreover, we find significant differences in amplitudes and lifetimes between the two models. [less ▲]