Asteroseismic analysis of 8 Kepler red giants

We determine oscillation frequencies, frequency separations, period spacings of mixed modes, and mode visibilities for eight cluster giants. The oscillation parameters show that these stars are helium-core-burning red giants.

The eight stars form two groups with very different oscillation power spectra; the four stars with the lowest {Delta}{nu} values display rich sets of mixed l=1 modes, while this is not the case for the four stars with higher {Delta}{nu}. For the four stars with lowest {Delta}{nu}, we determine the asymptotic period spacing of the mixed modes, {Delta}P, which together with the masses we derive for all eight stars suggest that they belong to the so-called secondary clump.