Seismology of δ Scuti stars in the Praesepe cluster II. Identification of radial modes and their associated stellar parameters

An analysis based on a comparison between observations and stellar models has been carried out to identify radial modes of oscillations in several multi-periodic δ Scuti stars of the Praesepe cluster (BU, BN, BW and BS Cnc). The assumption that all the stars considered have common parameters, such as metallicity, distance or age, is imposed as a constraint. Even so, there is a large number of possible solutions, partially caused by the rotational effects on the pulsation frequencies and on the stars’ positions in the HR diagram, which need to be parameterized. When pairs of radial modes are assumed to be present in every star, only a few similar identifications are found to be possible, corresponding to a metallicity of Z ∼ 0.030 and an amount of overshooting of αov∼ 0.20. They are associated with a distance modulus of ∼6.43 and an age of ∼650 Myr. Estimates of mass and rotation rates for each star are also deduced.