Poster abstract details

Since the early nineties it is accepted that the excitation mechanism of B-type pulsators on the main sequence is due to the opacity peak in the iron-group elements at $T\approx 200,000$ K. While theoretical non-adiabatic computations predict no $\beta$ Cep pulsators and few SPBs for low metallicity environments such as the Magellanic Clouds (MCs), recent variability surveys of B stars in the SMC reported the detection of a significant number of SPB and $\beta$ Cep candidates. Though the Fe content plays a major role in the excitation of $\beta$ Cep and SPB pulsations, the chemical mixture representative of the SMC B-stars such as recently derived does not leave room for a significant increase of the Fe abundance in these stars. Whilst abundance of iron-group elements seems reliable, is the opacity in the iron-group element bump underestimated? In this poster we investigate how the opacity profile in B-type stars should change to excite SPB and $\beta$ Cep pulsations in early-type stars of the SMC.