On the evolution of massive zero-metal stars

The evolution of zero-metal stars of 10, 15, and 25 solar masses has been followed through the core H burning and the core He burning phases to the phase of C ignition. It is found that such stars fail to reach the red giant region, burning both H and He at large effective temperature. Variations in the original amount of He in the range Y = 0.20-0.30 only marginally affect the structures of the stars. Zero-metal stars develop peculiarly small H exhausted regions, with larger electron degeneracy in comparison with Population II stars. The impact of supernovae from those stars is briefly discussed in terms of chemical pollution by Population III.