ASTEROSEISMOLOGY OF THE BETA-CEPHEI STARS .1. 16-(EN)-LACERTAE

16 (EN) Lacertae is a single-lined spectroscopic binary and an eclipsi ng variable. It consists of the well-known beta Cephei star and an inv isible secondary. Four pulsation modes, including a radial one, are fo und to be simultaneously present in the beta Cephei primary. We consid er all possible identifications of the observed pulsation frequencies with the computed ones for low-degree modes (l less than or equal to 2 ) in a series of stellar models covering the range of T-eff and mean d ensity consistent with the best available data. Only models allowing n o overshooting are taken into account and with this restriction the co nclusion that the rotation rate increases inward is unavoidable. There are ambiguities in the identification of the modes. We recommend obse rvations that should enable a unique identification and, as a result, yield precise model parameters and better constraints on the different ial rotation.