Evolution of single B-type stars with a large angular momentum content

Context. The Geneva Stellar Evolution Group has recently presented an extended database of rotating stellar models at three different metallicities for nine different initial rotation parameters and ten different masses corresponding to spectral types from early-F to late-O. With these grids we have contributed to the understanding of the evolution of single rotating stars, and we intend to use them to produce synthetic stellar populations that fully account for the effects of stellar rotation. However, up to now we still lacked stellar evolutionary tracks that rotate close to the critical limit during the whole main-sequence (MS) phase. This occurs because the flat internal profile of rotation imposed at the zero-age main sequence (ZAMS) is modified by the action of meridional currents immediately after the ZAMS, causing the surface rotational velocity to decrease abruptly until it reaches a quasi-stationary state.