Massive star evolution is still poorly understood, and observational tests are required to discriminate between different implementations of physical phenomenon in stellar codes. By confronting models with observed properties blue supergiants, such as pulsations, chemical composition position the Hertzsprung-Russell diagram, we aim at determining which criterion used for convection (Schwarzschi...

The effects of rapid rotation and bi–stability upon the density contrast between the equatorial and polar directions of a B[e] supergiant are investigated. Based on a new slow solution for different high rotational radiation–driven winds and the fact that bi–stability allows a change in the line–force parameters (α, k, and δ), the equatorial densities are about 10–10 times higher than the polar...