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Our main goals are to get a deeper insight into the evolution and final fatesof intermediate-mass, extremely metal-poor (EMP) stars. We also aim toinvestigate their C, N, and O yields. Using the Monash University StellarEvolution code we computed and analysed the evolution of stars of metallicity Z= 10^-5 and masses between 4 and 9 M_sun, from their main sequence until thelate thermally pulsing (super) asymptotic giant branch, TP-(S)AGB phase. Ourmodel stars experience a strong C, N, and O envelope enrichment either due tothe second dredge-up, the dredge-out phenomenon, or the third dredge-up earlyduring the TP-(S)AGB phase. Their late evolution is therefore similar to thatof higher metallicity objects. When using a standard prescription for the massloss rates during the TP-(S)AGB phase, the computed stars lose most of theirenvelopes before their cores reach the Chandrasekhar mass, so our standardmodels do not predict the occurrence of SNI1/2 for Z = 10^-5 stars. However, wefind that the reduction of only one order of magnitude in the mass-loss rates,which are particularly uncertain at this metallicity, would prevent thecomplete ejection of the envelope, allowing the stars to either explode as anSNI1/2 or become an electron-capture SN. Our calculations stop due to aninstability near the base of the convective envelope that hampers furtherconvergence and leaves remnant envelope masses between 0.25 M_sun for our 4M_sun model and 1.5 M_sun for our 9 M_sun model. We present two sets of C, N,and O yields derived from our full calculations and computed under twodifferent assumptions, namely, that the instability causes a practicallyinstant loss of the remnant envelope or that the stars recover and proceed withfurther thermal pulses. Our results have implications for the early chemicalevolution of the Universe.

Evolution and CNO yields of Z=10^-5 stars and possible effects on CEMP production