Constraints on the structure of the core of subgiants via mixed modes: the case of HD 49385

Context. The solar-like pulsator HD 49385 was observed with the CoRoT⋆ satellite over a period of 137 days. The analysis of its oscillation spectrum yielded precise estimates of the mode frequencies over nine radial orders and distinguished some unusual characteristics, such as some modes outside the identified ridges in the échelle diagram and that the curvature of the ℓ = 1 ridge differs significantly from that of the ℓ = 0 ridge.