INFLUENCE OF MASS-LOSS AND CONVECTIVE OVERSHOOTING ON THE EVOLUTION OF MASSIVE STARS

Evolution of massive stars losing mass with the rate M H αL/V∞C is computed (for α=1,2,7). It is shown that observed mass loss rates correspond to α≈0.3 and, therefore, mass loss by stellar wind cannot play any significant role in the evolution of normal massive stars. However, for several types of massive stars (WR, OH/IR, X-ray sources) enhanced mass loss explains their peculiar features. Computations of evolutionary sequences of massive stars with convective overshooting taken into account (as a formal increase of the convective core) show that a significant broadening of the hydrogen-burning band in the H-R diagram may be obtained. © 1979 D. Reidel Publishing Co.