  Two key reactions of hydrostatic nuclear burning in stars have recently been
revised by new experimental data - the 14N(p,gamma)15O and triple alpha
reaction rates. We investigate how much the new rates influence the evolution
of low-mass, metal-poor and metal-free, stars and of an intermediate-mass star
of solar-type composition. We concentrate on phases of helium ignition or
thermally unstable helium burning. Our global result is that the new triple
alpha rate has no significant influence on such stars, but that there is a
noticable, though small, effect of the new 14N(p,gamma)15O rate, in particular
on the core helium flash and the blue loop during core helium burning in the
intermediate-mass star.
