SEISMOLOGY OF DELTA-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 mod els has been carried out to identify radial modes of oscillations in s everal multi-periodic delta Scuti stars of the Praesepe cluster (BU, B N, BW and BS Cnc). The assumption that all the stars considered have c ommon 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 frequencie s and on the stars' positions in the HR diagram, which need to be para meterized. When pairs of radial modes are assumed to be present in eve ry star, only a few similar identifications are found to be possible, corresponding to a metallicity of Z similar to 0.030 and an amount of overshooting of alpha(OV)similar to 0.20. They are associated with a d istance modulus of similar to 6.43 and an age of similar to 650 Myr. E stimates of mass and rotation rates for each star are also deduced.