T_eff−log g plane showing the low-mass He-core WD evolutionary tracks (final cooling branches) of Althaus et al. (2013). Numbers correspond to the stellar mass of each sequence. The location of the ten known ELMVs (Hermes et al. 2012, 2013c,a; Kilic et al. 2015; Bell et al. 2015, 2016) are marked with large red circles (T_eff and log g computed with 3D model atmospheres corrections). Stars observed not to vary (Steinfadt et al. 2012; Hermes et al. 2012, 2013c,a) are depicted with small black circles. The gray squares and triangles on the evolutionary tracks indicate the location of the template models analyzed in the text. The dashed blue line corresponds to the blue edge of the instability domain of ℓ = 1g modes according to the nonadiabatic computations of Córsico & Althaus (2016) using ML2 (α = 1.0) version of the MLT theory of convection.