We calculate a grid of models with and without the effects of axial rotation for massive stars in the range of 9 to 60 M⊙ and metallicity Z = 0.004 appropriate for the SMC. Remarkably, the ratios Ω/Ωcrit of the angular velocity to the break–up angular velocity grow strongly during the evolution of high mass stars, contrary to the situation at Z = 0.020. The reason is that at low Z, mass loss is...

The red hypergiant VY CMa and the more typical supergiant Betelgeuse provide clear observational evidence for discrete, directed gaseous outflows in their optical infrared imaging, spectra, light curves. In very luminous CMa, mass loss estimates from bright knots clumps, not only dominate its measured overall loss, but explain it. lower luminosity Betelgeuse, similar of circumstellar condensati...

Two-dimensional simulations of mixing and fall back in non-rotating massive stars have been carried out using realistic initial models for the presupernova star and assuming standard spherically symmetric explosions of 1.2×10erg. Stars of 15 and 25 M with both primordial and solar composition were modeled. The zero metallicity supernova progenitors were compact blue stars and the amount of Rayl...