is a little wider than for $Z=0.015$ (central-left panel). This is a consequence of a larger extension of the loops towards the higher effective temperatures for lower metallicieties. As expected, an increase in $Z$ results in wider instability area on MS and beyond TAMS.

The upper panels show an effect of opacity tables on instability domains for $Z=0.01$, but the main conclusions are the same for every tested metallicity. There are significant differences on the MS phase, due to a long-known fact that for OP tables instability starts earlier than for OPAL tables. During the hydrogen shell burning phase and on the blue loop the differences are very subtle. The loops and instability areas have slightly different shapes but generally they are similar for both sources of the opacity data.

In the central panels we compare instability domains for models with $Z=0.015$ calculated without (the central-left panel) and with mass loss (the central-right panel). For $T_\mathrm{eff} > 10^4$ we used the wind’s scheme of Vink et al. (2001) whereas for $T_\mathrm{eff} < 10^4$ a recipe of de Jager et al. (1988) was adopted. We do not study very massive models and hence the amount of mass which is lost during 