Nonlinear Radial Pulsations for Hot 20-M⊙ Models

Abstract

AbstractWe present the results of calculations that predict a radial pulsation instability region for hot 20-M⊙ stars within a narrow band around Teff = 22,000 K. These models have exhausted core hydrogen and are undergoing shell hydrogen burning, and have luminosities similar to the most massive β Cephei stars, but are slightly cooler and more evolved. The pulsations grow to a radial velocity amplitude of ~20 km s-1with a period of ~0.75 d. The amplitude increases for higher Z and lower Y models.