Massive zero-metal stars: Energy production and mixing

Institut für Theoretische Astrophysik, Universität Heidelberg, Tiergartenstraße 15, 69121 Heidelberg, Germany

Corresponding author: C. W. Straka, cstraka@ita.uni-heidelberg.de

Received: 21 March 2001
Accepted: 2 April 2001

Abstract

Time-dependent nuclear network calculations at constant temperature show that for zero-metal stars ≳ (i) β-decay reactions and (ii) the ¹³N(p,γ)¹⁴O reaction must be included. It is also shown that the nuclear timescale in these zero-metal stars is shorter than the mixing timescale and therefore the assumption of instantaneous mixing across convective regions is not fulfilled. We conclude that proper modeling of these processes may alter the evolution of massive zero-metal stars.