Recently , \citet bailey-2015-01 made a direct measurement of the Iron opacity at the physical conditions of the solar tachocline .
They found that the wavelength-integrated Iron opacity is roughly 75 % higher that what the OP and OPAL models predict .
Here , we compute new opacity tables with enhanced Iron and Nickel contributions to the Rosseland mean opacity by 75 % each , and compute three dense MESA grids of evolutionary models for Galactic O- and B-type stars covering from 2.5 to 25 M _ { \odot } from ZAMS until T _ { eff } = 10 000 K after the core hydrogen exhaustion .
We carry out non-adiabatic mode stability analysis with GYRE , and update the extension of the instability strips of heat-driven p- and g-mode pulsators , and the hybrid pulsating SPB - \beta Cep stars .
We compare the position of two confirmed late O-type \beta Cep and eight confirmed hybrid B-type pulsators with the new instability domains , and justify that \sim 75 % enhancement , only in Iron opacity , is sufficient to consistently reproduce the observed position of these stars on the \log T _ { eff } versus \log g plane .
We propose that this improvement in opacities be incorporated in the input physics of new stellar models .