EHB evolutionary tracks covering the ﹩\mathrm{log}\,g﹩–T_eff region where sdB stars are observed. The seven tracks correspond, respectively, from left (high T_eff) to right (low T_eff), to objects with a ZAEHB envelope mass ﹩M_{\mathrm{env}\,}=0.0001﹩, 0.0002, 0.0007, 0.0012, 0.0022, 0.0032, and 0.0042 M_⊙. The core mass is ﹩M_{c}=0.4758﹩ M_⊙ for all sequences except the first and third (from the left), which have ﹩M_{c}=0.4690﹩ M_⊙. In a given sequence, each filled square (for the sequences with ﹩M_{c}=0.4758﹩ M_⊙) or filled triangle (for the sequences with ﹩M_{c}=0.4690﹩ M_⊙) represents a model available for the pulsation calculations. The number along each track indicates the model for which there is a change of regime in the period evolution (see text).