A zoom of the T_eff − log g diagram shown in Fig. 1 showing the region where is located the only known (so far) pulsating ELM white dwarf, SDSS J184037.78+642312.3 (Hermes et al. 2012) displayed with a red circle. We include the approximate ℓ = 1 g-mode blue edge of the theoretical ELM instability domain derived by SEA10 (thick black solid line), and the ℓ = 1 g-mode blue edge computed in this work (blue solid line) for all the sequences considered, included that of M_∗ = 0.17 M_⊙, and extended towards lower gravities (blue dashed line). We also show our ℓ = 1 p-mode blue edge of instability (thin dotted line).