= AGB envelope-loss and core-growth timescales
{c}
{title2=$t_{\rm env}\sim M_{\rm env}/|\dot M|,\quad t_{\rm grow}\sim\Delta M_c/\dot M_c$}
The fate of an <Asymptotic giant branch> star depends on whether its envelope is removed before its core reaches the next ignition or instability threshold. The approximate envelope-loss time is $t_{\rm env}=M_{\rm env}/|\dot M|$, while the time to add a required core <mass> $\Delta M_c$ is $t_{\rm grow}=\Delta M_c/\dot M_c$. Shell <stellar nuclear fusion> grows the core; <third dredge-up> can reduce the net growth. If $t_{\rm env}\ll t_{\rm grow}$, shell fuel disappears first and a <white dwarf> remnant is favored. The opposite ordering permits further core growth but does not by itself specify whether <carbon burning> is stable, explosive, or followed by further evolution. Both rates change with time, so the estimates guide rather than replace a stellar model.
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