Is the additional increase of the star luminosity due to partial mixing real?

Abstract

The partial mixing of matter between the radiative envelope and the convective core in the early type B--star produces an additional increase of star luminosity during the main sequence evolution. The high quality data on stellar mass and luminosity defined from the studies of detached double-lined eclipsing binaries are used to check the existence of such additional increase. It is shown that the additional luminosity increase does not contradict to the observed data of high quality, if the intensity of partial mixing is restricted by the observed increase in surface helium content.