A possible solution to the cepheid mass problem?
With new, smaller distances of the Cepheids, as determined recently by Schmidt (1984) and by Böhm-Vitense (1985), smaller pulsational masses are obtained than previously. Giant companions of Cepheids show that the luminosities of the Cepheids are too large in comparison with those of the giants. If increased mixing, for instance by convective overshoot at the boundary of the convective core during the main sequence stage, is responsible for this, then we expect an increase in the luminosity of the Cepheids of a given mass by approximately a factor of 4 as compared to conventional evolution calculations. Taking into account both of these effects we find good agreement between the corrected evolutionary masses, the pulsational masses, the dynamical masses, the giant companion masses and the Wesselink masses. The bump masses are only slightly smaller than the other masses.
KeywordsMassive Star Stellar Evolution Close Binary System Evolutionary Track Convective Core
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