and mass loss parameter $N=100$ during the hydrogen burning.[]{data-label="bar_fig8"}](figure8.eps){width="82mm"}

![Idem dito. Pregalactic Population III stars with metallicity $Z=10^{-9}$ and mass loss parameter $N=100$ during the hydrogen burning.[]{data-label="bar_fig9"}](figure9.eps){width="82mm"}

![${\rm log}\,T-{\rm log}\,\rho$ plane for $100$, $120$, $150$, $200$ and $250\,M_{\odot}$ pregalactic Population III stars with metallicity $Z=10^{-9}$, and mass loss parameter $N=100$, during the hydrogen and helium burning phases.[]{data-label="bar_fig10"}](figure10.eps){width="82mm"}

### e) $\rho-T$ plane {#e-rho-t-plane .unnumbered}

In the $\rho-T$ plane the galactic and pregalactic very massive Population III mass losing stars occupy the upper loci of a nondegenerate and nonrelativistic gas. In this zone there is an upper boundary at which pair production effects could become important. The most massive stars tend to approach to it, however, our models are below this boundary. Regarding the gas in thermodynamic equilibrium, mass losing stars studied here are dominated by radiation pressure. Fig. \[bar\_fig10\] shows the evolution of conditions in the centres of stars.

### f) HR diagram {#f-hr-diagram .unnumbered}

As in the conservative case, the locus of very massive Population III stars in the HR diagram is in the left upper part. Pregalactic stars are hotter than the galactic ones. The most massive stars are the most luminous. Depending upon the star’s initial mass and 